That seems like a great way to remove the paper. I do wonder though, how much paper made it into the drain and will eventually bog down in the trap. Perhaps soaking it in a tub unrelated to the plumbing would be a better option. Also, try using newsprint paper. You can buy a ream of it on Amazon. It goes through your printer easily or you can trace on it just as easily. I find it just as nice as foundation papers and not nearly as expensive. Also fellow quilter.....remember when you are removing your papers to recycle them!!!