It works great. I've never had it clog a valve. I've mostly used it on presta valves, it's fine.

I had an intance this spring when I had mixed slime and orange sealant, the the orange had dried and if it wasn't for the slime, I'd have had to put a tube in.

You can get a little on your hands, it's not the end of the world. Don't install it indoors.

It has it's place in the cycling world.

Don't avoid it because people who used it wrong had trouble with it.