I'm so glad I found this post!

My rabbits smell horrible, they are in the bathroom, and I clean their litterbox daily. It's just gross. I also saw a different post about vents, so I cleaned them, but they weren't bad at all, so I think it's just the urine. I started adding acv, and they'll drink it, but how long does it take to start working? Also, the smell was less when we ran out of rabbit pellets--do they have to have pellets, or can they do well on hay with some fresh veggies?
I'd like to keep them in the house, they get cuddled so much more plus out of cage time, but the smell is overpowering.