Mine are all litter trained, so they poop in the litter trays. They will wee wherever they want and they can't really be trained to wee in a specific place unfortunately >.<
I sweep (with a dustpan and brush) and wipe down the cage (with baby wipes, unscented) every evening and completely empty and change the litter pans every 3 days. But thats with all 8 in one cage.
When I had 2/3 rats living together i spot clean every 2 days (pick up poop and wipe levels) and replace all the substrate every week.
I also re-organize all their toys and hammocks and completely rearrange the cage every week too