I think I'm going to try it with my next B&W roll...just need to get some fixer. I'm very intrigued, and it's appealing not to have to deal with harsher chemicals. I'm also reading that if used to develop colour negatives, it gives them a sepia tone. Pretty cool too...
I'm loving this sample:
More here, the portraits look fantastic too... https://www.diyphotography.net/caffenol-processing-film-coffee-supermarket-ingredients/