Coffee enemas are used with success for a variety of conditions. They've been extraordinarily helpful for me for Lyme disease, for overall well-being and promoting detox.
I was trying to look up why they work, and it seems like once again, it's hormesis. Cafestol and kahweol in coffee are potent Nrf2 activators, among the 6 most potent, and rectal administration is a great way to get those hormetins into the bloodstream.
Pretty much anything that has truly helped me with Lyme has been hormesis: ozone (causes a rebound response to oxidative stress), MMS (oxidative stress), curcumin, ashwagandha, green tea extract, coffee enemas, vegetables.
I also have to wonder whether some of the benefit of the alkaline diet is that it includes a lot of hormetins and Nrf2 activators -- green vegetables.