Ive tried it. I used a break pad off a bike and it worked good to lock the break but the rubber on the pad wore way too fast. I get pics of it but i allready threw it away. Here it is before I threw it away.
You can see in the picture its allready wearing away and that was only from about an hour or less of light riding...
Basically, to sum it all up, its not worth it. You get great lock but thats about it. The pad wears too fast for pretty much anythingbut if your the type of person that only does tailtaps or back wheel stall tricks and doesnt use your brake for anything else, you might want to gove it a try. BTW i am no longer riding the break or pad because both are broken.