Also, when you clean his litter box do you just dump the litter and get new, or do you clean it with a water / vinegar solution every so often? Plastics will absorb the smell of urine, so a vinegar scrub every so often helps a lot. And what you use as litter can help too, I use newspaper for my boy because he will not accept anything else (he’s so picky!) and it doesn’t absorb smell at all … I use wood pellet litter (pellet, no shavings!) for my girl and her room doesn’t smell much at all because it absorbs the smell so well.
Any carpet/rugs can be cleaned with baking soda and then vacuumed, helps a TON to rid my carpet of any smells they may make. I just overnight leave baking soda on the carpet with the buns locked securely away in their night time rooms and vacuum it in the morning before I let them out.
My male is not altered yet (waiting for the vet to OK it) and sometimes he’ll go around chin rubbing / leaving a few droppings around and the smell is pretty strong because of his scenting. I use nature’s miracle to rid that smell, since vinegar doesn’t seem to do as good a job (bun can’t be around it though as it’s alcohol based).
For leaving him out while you’re not there… I have a bunny proofed area for my male when I am not around he stays in it (his bedroom, my bedroom and the bathroom) and I just make sure there is nothing he can chew or hurt himself with in them. My girl has the laundry room all to herself. I never put either of them into a cage.