Really interesting that this topic came up. One day last week, I was brushing my teeth, wearing a black t-shirt, and drooled down my front (doesn't that always happen when you're in hurry to leave the house?) Of course I had to change my shirt, couldn't get the toothpaste out just by wiping it with a washcloth, but knew it would come out in the wash--Eureka moment, experiment time when I got back home--Toothpaste! It works! I diluted white toothpaste in about 1 tablespoon of water to the consistency of pancake syrup (experiment to see what works for you and won't plug up your sprayer), put it in a small fine mist sprayer, held the sprayer about 6-8 inches above the stencil, sprayed lightly a couple times and it worked! First few times I was too close and I had seepage under the stencil, it dried very quickly, didn't rub off, but washed out just fine. I did use a couple sheets of paper at the edges of the stencil to catch the overspray, but there wasn't much, and the stencil rinsed off easily also under running water. Next, I'm going to dilute with rubbing alcohol, to see if it dries faster, doesn't rub off, and washes out ok. Haven't done that yet, just excited that my first experiment worked. If you try this, please post your results, I hope it works for you too. Oh, I also moistened a foam make-up sponge and rubbed the toothpaste on, works well too, but the spray is faster. The only thing I didn't like, but can definitely live with is the line is the thickness of the stencil cut, I like my lines a little thinner.