A bass sucks in a crawfish on the sandy bottom of a lake. Most of the sand is expelled out the gills. I'm sure the bass swallows some sand though. Glass beads are glass/sand. Not some un-natural substance.
The glass beads WILL scratch your injector. More specifically the piston and nozzle. The tube seems to be OK. Even scratched the injector works fine and oiled o-rings seal as normal.
Here are some Sticks with 120 grit.. Baits are transkucent and bright and show flake well.
4 oz soft plastic
2 heaping tblsp glass beads.







Even color changing motor oil works

Mo Milk
