I use volunteers to tube my blanks, and this is how I have trained them to do it. We use epoxy when there is time to let it dry overnight, or thick CA if we are going to need the blank the same day.
I have them plug one end of the blank with play dough, then put an insertion tool in the other end. They mix the epoxy on a piece of paper (I use old PSI catalogs LOL) and when it is mixed they spread it out in an area big enough to roll the tube in. They roll the tube in the glue, then insert it in the blank, rotate it, pull it back out and roll it in the glue again and insert it and rotate it then pull out the insertion tool. We use 15 or 30 minute epoxy because we are not going to use these for at least 24 hours. This allows them to mix up enough epoxy to tube ten blanks or so at a time before the glue begins to set. Rolling the tube in the glue makes sure there are no blank spots on the tube, and doing it twice makes sure there is enough glue in the blank.
We do basically the same thing with thick CA, but only do one or two blanks at a time, putting a strip of thick CA on the paper long enough to roll the tube in, except we don't pull it out and reinsert it with the CA.