Flush the toilet, and then clean it with bleach. For added protection, have the swirlee wear goggles, maybe earplugs and a nose plug, and have them close their mouth.
If you’ve watched Jackass, Steve-O volunteered to sit inside a porta-potty as it was hurled into the air. If you don’t mind seeing shit fly everywhere, you can look at the PPE he was wearing. Your swirly will be like that stunt, but much cleaner.
Slower? Have you not seen all the beans? Maybe that’s just my feed.