Does no-one just throw a leaf in the air or light a roll up or wet your finger ?? Or even just feel it ?? Am I missing something ??
Don't worry aboyt chalk, just scoop up some fine wood ash the next time that you have a fire!
Use foot powder, then at least it's good for something else.
there must be loads of stuff out there you could use, a hand full of bog cotton from your tinder box some flour out your bag a pocket full of dandelion heads, reed mace the lint oot yer belly button.