Vanilla and vinegar can both reduce odor but they are used in different ways. Vanilla can be added to the drinking water (I have tried this when I bred mice, I didn't notice and significant difference in the smell of male urine.) Vinegar absorbs odor so its nice to have it near a cage (outside the cage) in a wide bowl and it will absorb odors to some extent. Though it can also leave the area smelling of vinegar.
I don't think sand is a good substrate for mice or rats...they are not desert mammals (though maybe spiny mice will be happy, I do believe they are more desert dwelling than the typical domesticated mouse). If you really want to go to a more natural style setup for mice, a dirt/soil mixture that is well packed would be more natural.
If you only have rainbow boas...even babies, they can eat pinky rats no problem. Rats are not as smelly as mice (male rats don't produce the same heavy musky scent of male mice). They will need to be regularly cleaned and I find the odor stays down better, if you give them plenty of space (far more than the typical large cat litter space used in racks for rat trios).
Avoid scented substrates too...perfumes can act as an irritant...and having once used a scented kitty litter for a cat I was fostering, it nearly killed me..but then I happen to be sensitive to strong perfumes. Makes my nasal passageways burn and my throat burn...I expect it is much like how I assume sniffing cocaine must be like, without the 'high' (I don't' think sniffing powder up your nose can be all that 'comfortable' I expect it would burn like heck).
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PHLdyPayne
Forum Princess