To be fair, a properly raised chinchilla is unlikely to bite. The only one I've had who had a tendency to bite was a rescue who was in terrible pain. She's a sweetheart now but it took a while to get her to relax.
As for gerbils, they're desert animals and have very concentrated urine but little of it. I found that they were very clean, relatively odourless animals but I guess it depends on how you keep them.
Chinchillas are also desert animals and relatively odourless but they produce a LOT of poo. I keep mine on cage liners and it's easy to clean them out every day or every other day, it just means a lot of laundry
One other thing to consider with chinchillas is that you absolutely
must be able to control the temperature. If it gets too warm they can die.