You use it while still seated so the water drips back into the toilet bowl; no mess there
I do use paper too to dry or further cleaning if needed
If you look at the 3rd picture on the link above you'll see that the sprayer lowers down while spraying and then retracts back behind a guard; I've never seen the guard or sprayer themselves get dirty from general toilet use
No, the water pressure isn't so intense that it would scatter debris everywhere
I first used one at a friend's house and found it does a far better job cleaning compared to just paper alone and would certainly recommend giving it a try
themadcodger