sand worked...or glass lol the popcorn salt is hard to come by in larger containers or bags...i found it in walmarts or meijers but it was a small container...and not cheap....i do a cup or two of koser salt in the bullet and it works out fine never had a harding issue or clumping....just dont store it outside after im done with my baits what i have left comes inside with me....if you like salted baits you need to get a bullet you illbe happy you did....