I usually use paraffin and powdered charcoal (or wood shavings), in combination to flux/reduce my bullet alloy when casting bullets.
I recently was given a fairly large quantity of crayons from one of my wife's/grandchild's abandoned projects with the instruction of: "...burn these.". I immediately thought of using them for fluxing my bullet alloy. The "kicker" is, that I do not need them inasmuch as I have just about a life time supply of boxed paraffin from one on my wife's other abandoned projects that I use for flux... so I am not hurting for fluxing components but I do not like to waste anything.
So my question is (only for those who have actually used crayons for fluxing bullet alloy), how well did it work or was there some negatives you observed?