I need to get some screens for my herbalAire and I'm trying to decide what I should be looking for. I will want a couple that I can use on top of the crucible to reduce particles from shake from clogging the whip or entering the bag. I also may want replacements for the MP screen. Do I wast steel, brass, or aluminum? Since I won't be putting flame on them it probably doesn't matter, but since I am vaping to reduce harmful stuff I suppose I should use what is best.