These can go through the wash. I've used them on custom tshirts I made for a kids party before.
The paper commonly seen in stores is for Inkjet only! If you have a laser printer, you'll have to search a bit to find the right paper. Just make sure you check before you buy.
I've always partially lined my clips b/c the local boutiques don't line them (only a small strip on the top) and I wanted them to be similar but I may have to change if I want to use this technique.