Here's a page I found when researching these wicked little pens. I bought what I thought was a wholecloth marked with pencil -- turns out it was Frixion. I haven't tried these methods, but I have this page bookmarked as I suspect I may need it by the time I finish. Hope it helps!
http://quiltskipper.com/2015/08/13/f...-need-to-know/
As a side note, Crayola Ultra Clean markers are on sale at Target right now for
$1.97 / 10 markers (well, 9 markers -- I don't recommend using the yellow one; it will come out, but not as easily as the other colors)
http://www.target.com/p/crayola-ultr...s/-/A-15225907
They always come out. I soak it in the tub with a Color Catcher & cold water for 45 minutes, then I toss it in the wash (cold water, gentle cycle, Tide Free) and it comes out with zero marks. Plus, you can't beat the price! I've left it on quilts for over a year -- in an outdoor storage locker (I know! I know! Phone the Quilt Police!) while I was in the hospital for several months -- and then I ironed it; and then it sat in my studio space in full sun for several more months because I left it on the machine most days after my 10 minutes of quilting time wore me out for the day. If Ultra Clean markers can come out under those conditions, I feel confident there is nothing that would keep them from washing out period.
Hope you find something that works & that one day you'll look back on this & laugh.
Blessings,
Bree
Ha! Guess I'm a slow typist! Just saw PaperPrincess recommended the same website I did. Great minds think alike! 