We adopted a pair of gerbils from our local shelter a few weeks ago. It's been 30+ years since I have had gerbils. Back then enrichment was not really common beyond some bedding to shred and tubes to chew. Among their in-cage enrichment, we got them a small sand bath similar to the one pictured below. They seem to enjoy bathing in the sand and particularly using the sandbox as a bathroom. There is almost no odor at all from the cage as a result.
The packaging of the sand says that gerbils and hamsters only need to bathe a few times a week. We are wondering if there are downsides to leaving it in their cage all the time.
Can they bathe too often? We clean out the feces and sand clumped from urine twice a day, so it is clean most of the time and replace the sand completely each time the cage is changed. Most of the concerns about leaving the box int he cage all the time (e.g., here) seem to suggest soiling the sand.