I used a cloth diaper service when I was in college and grad school. It worked very well.
I was their only adult customer when I started, but the next year their ads all advertised that they did adult diapers.
I had to buy a dozen diapers (prefold flannel) and plastic pants (snap-side flannel lined vinyl) from them. They weren't terribly expensive, but they were durable. The diaper service supplied baby diapers for soakers. I used a lot of them. The service also supplied a diaper pail and the soaking chemicals. The service came by one a week to pick them up.
One of the things I really liked about the service was that they boiled the diapers, so they were completely sanitized. You can't really do that in a home (or laundromat) wash machine.