Stefany's place is good for a few days, especially if you want to ride in cheap for the carnival.
The accommodation looks as described, is clean, has hot shower and all basic amenities. The host is very responsive and will help you in any way possible.
The location might be a pain point for some since it's the favela (as described in the title). Generally, it is very safe on the inside but there may be times when people ask you as a tourist why you're there.