Good info. I've been considering the alternatives to lava rock for my Camp Chef version, mostly because I'm continually losing some of the smaller stuff. Re-thinking the problem, I think the issue is that Camp Chef just cheaps out and uses a pretty mixed-size lava package, so a lot of it falls out. I think I'll just go through the lava rock and keep the bigger chunks and add a few more to offset all the little stuff I've lost...