i hand quilt and i always mark my quilts w/ just a #2 pencil...The lead markings actually eventually just wear off.
I got the idea from a quilt group that had the Mr Clean Magic Erasers sitting on the quilts - and i asked what they were for. The ladies told me they use them to erase pencil marks....
So - i had to try it tonite....W/ the quilt laying on a hard surface, you just rub the Magic Eraser over the markings and VOILA......pencil marks are gone!! I didn't even have to rub real hard!