Maniac I've never heard of a chalk wheel, how do you use it?
I usually mark dark fabric with a Clover white pen that irons out like the Frixion pens (which I also use). But sometimes I use a whole different thing...Glad Press-n-Seal. Sounds odd I know but it works great. Just press it on, draw your line, sew and it peels right off without leaving any marks or residue. When I use this I don't have to worry about erasing anything. It's useful in some situations.