ensoul wrote:
sorry 2 cats and 2 litter boxes, they're brothers


ensoul


Well, if the smell is the big issue you can start with what they are
consuming... because usually if the food they are consuming doesn't
agree with them or isn't the best what comes out the other end will
smell horribilis! :-D

So, what do you feed them? ...and have you considered switch, gradually,
to something else?