Until it dries, you can remove it with acetone. It doesn't take long for a small dab of it to dry, though. Only a couple minutes. That's more likely what you'll get on you if you do.
I love this stuff for sealing gaps. It's perfect for keeping rodents out.
I expect you'll get the space mostly full with 2 cans. You might get better results applying it in 2-3 inch layers instead of all at once.