I found something locally to use as filler. Go to a Michaels or Hobby Lobby or some other crafts store. Go to the section where they sell scrap book supplies, least I think that is what they call it. Somewhere in that area you will find little jars of granular material that is use when you rubber stamp designs on paper. You stamp wet ink, sprinkle the powder on it and then dump off what doesn't stick.
The jars I found cost about $3.50 each. They come in all kinds of colors and textures. Sparkle, matte, gloss finish. Black, blues, greens, tan, gold, silver, what have you. I bought about 5 bottles of different ones and use them right out of the bottle or blend them to get different colors.
You just put a little pile of the powder in the void and touch a drop of CA right beside the pile. If you drop it right on the pile of powder it will sometimes splash the powder right out of the void. So let capillary action draw it into the powder in the void. I find that the little mouse tail CA applicators help with not getting too much CA in the void.