Looking for a decent "small brush" to use?
Try an old toothbrush!
You can run it along the blanks while the lathe is running, and you can also turn the lathe off and rotate the blanks by hand while you run the brush across the blanks side to side (lengthwise). This may help clean out those wood pores.
If you have access to compressed air, this does help a good bit to! If you don't, then concentrating your breath may help more than just huffing and puffing at it. Blow the dust away by using a straw, so you can direct the pressure right where you need it!
Water can raise the wood grain. When sanding flat surfaces like table tops or cabinetry work, wiping with a wet cloth will cause the grain to rise. One part of the grain will not absorb as much water and will remain lower. When you sand it flat again while in this condition, the raised grain will then drop down below the harder grain, giving you a beautiful surface that is a good bit more durable than the overall piece of wood. The problem with this in penmaking is that you don't want a bumpy surface like that - unless it was intentional that the customer feel the wood grain!
Wiping the blank with 95% isopropyl alcohol doesn't do this nearly as bad ... it DOES have 5% water in it, so you don't want to soak your blank in it. Denatured Alcohol (DNA) has about the same water content. The alcohol can help carry dust and debris away from your blanks, and then evaporates quickly.
Acetone doesn't absorb water, from what I hear around here, so it's a better choice for cleanup.
The following is how I finish my blanks ... I like the way I do it. You can try it if you want, perhaps you'll like it to.
*Sanding*
Turn to the shape I want ...
Sand with 180 grit Abranet to final dimensions. (Mirka Abranet is a nice fabric mesh sanding pad to use ... I get 10 - 12 pens out of half a single piece.)
Wipe with dry bit of paper towel to remove any excess dust and grit.
Continue sanding with Abranet all the way up to 400 grit (I'ld go higher, but the multipacks offered by PSI only go up to 400 grit.)
Wipe off or brush off with paper towel to remove excess dust and grit.
Sand with 1000 grit wet-or-dry sandpaper. (I get mine at Harbor Freight ... if I had 1000 grit Abranet I'ld use that for sure.)
Wipe with paper towel with a bit of 95% rubbing alcohol.
Turn lathe off to check the blank ... examine for pores and if they contain anything they shouldn't ... if they do, then brushing with my old toothbrush and a blast of compressed air or two is indicated.
*Finishing*
Using blue shop towels (from the auto parts store), I fold it 3 times lengthwise to form a long strip, and cut it in 3/4" lengths with a pair of scissors to form my applicator pads. Shop towels work like paper towels, but they have far less lint and are softer, so they leave a bit better finish behind when used over paper towels.
When wet sanding, I use normal cheap paper towels for wiping the blank dry...
I start the finishing process by applying a few drops of Minwax Stain'n'Seal (natural amber color) to an applicator pad (blue shop pad, I'll just call it a pad from now on) and apply it to the spinning barrel blanks. You can take the lathe speed up a bit here and really polish it in, but I don't do this for more than 3 to 5 seconds ...
Next, I grab my little tube of Harbor Freight brand superglue (CA) and apply a few drops to the same pad I just used - it's still wet! and I turn the lathe speed down to the SLOWEST SPEED it can go. (YOU DO NOT WANT CA FLUNG ALL OVER YOU, YOUR LATHE, OR YOUR SHOP!) With the lathe at slowest speed, apply the CA in a single smooth motion over your barrels. You can go left or right, I prefer to go quickly right-left-right over the span of 3 seconds. You'll speed up as you get more practice at it.
The first coat of CA is dry to the touch within 10 seconds, but I like to leave it a bit longer .... I apply the next coat of CA about 20 seconds after the first, but I use a fresh pad for this coat as well as every coat following. I like to wait about 5 minutes or so between coats (sit down, watch anime, ect), and put 6 - 12 coats on a nice pen.
I turn off the lathe to examine the finish ... should be no white from the superglue, no little specks of blue shop towel hanging about ...
I use wet sanding from this point on ...
Using 1000 grit wet-or-dry paper, I dip the paper in a small bowl of water (I also protect my lathe bed from water!), and I begin sanding with the lathe at around 1000 RPM. I sand till the surface is uniformly smooth, dipping the paper back into the water to remove slurry and get fresh water when needed. I also turn the lathe off to sand laterally along the barrels, to break radial lines.
(VERY IMPORTANT STEP HERE I ALMOST FORGOT TO INCLUDE!! Take an exacto-knife or other small sharp blade and very carefully, right at the edges of the blanks and bushings, score through the CA. This will help you remove the blank from the mandrel later without ruining your finish!)
I then continue wet-sanding with micro-mesh sanding pads - Hobby Lobby has a decent set for around 15 dollars. You get 3200, 3600, 4000, 6000, 8000, and 12,000 grit pads, about 2" by 2", and they are double sided. The 3200 grit does a lot of grunt-work, since I jumped up from 1000 grit, but 2000 grit paper is harder for me to come by or I'ld use it.
I dry the blank off with paper towels between each grit, to clear away the slurry and any remaining grit. I also sand laterally at least every other grit, to remove radial lines.
After I've finally reached 12,000 grit, it's time to polish the barrels!
I use Meguair's Plast-X. This is a plastic polishing compound that you can buy at an auto parts store. The nice thing about this is that it has a grit that breaks down while it's working, reaching 30,000 grit by the time it's done. This is what gives a beautiful glassy shine to my finish. I apply this at low speed, so that it doesn't just get flung off the barrels, but then I push the lathe to max speed and really buff it in for a good minute or two.
I leave the lathe running at high speed and apply Turtle Wax Hard Surface (liquid). I rub and buff this in for around a minute as well. This helps protect the CA underneath, and also helps repel water and fingerprints.
Good luck with your endeavors, hope you find a finish that satisfies you soon!