I read these posts so bought some Crayola washable markers. Tried each color on a piece of quilt fabric. Then I used my wet rag and wiped them. Color didn't budge. I was using cold water. I don't wash my quilts after making them so not sure if that's what is needed with these markers. I just keep a wet rag to wipe the blue ink off the Mark-B-Gone thing. What's the trick with these markers?? Thanks.