A little perspective, here, please. Humans sell lubricant specifically marketed for introducing foreign objects to their lower digestive tract. We also sell home enema kits without a prescription at local drugstores. You don't need clinical supervision. At best, they could provide donor screening to reassure you that you aren't going to give yourself a new disease. If you know the donor, you could probably do at least as well just by observing them for a period of time.
Putting someone else's poop in your colon is not that disturbing when you realize that it already had your poop in it. It wasn't exactly squeaky clean before the procedure.
And believe me, the guy squirting strange feces into himself as a personal experiment has thought about this a lot harder than you. Even the guy doing it for a bar bet has probably invested more doubt.
