Here is a challenge for you, get some dog crap on your hand and spray it with a garden house then sniff your hand. Unless you are soaping and scrubbing your ass deep, it isn't going to be 100% sanitary regardless of using paper or a bidet. They are nice, but in the end it doesn't matter.
After you're done wiping as thoroughly as you will, run your hand or another piece of toilet paper through your butt and smell it.