I have nineteen rats between four large cages, my cleaning routine is a follows:
After my son is down and before I go to bed (which leaves four to five hours), I do free-time rotation in my rat room. Same-sex groups spend time out in the play area while I change litter pans, spot clean, and inspect the condition of their cage furniture. If anything feels scummy, it's removed to either be washed or tossed. Replacement items are installed if needed. Water bottles are topped off. Food is refreshed.
My liners are two layers of towel sewn under fleece. Every other day, I replace the liners (regardless of condition) with fresh ones, shake them out if needed, then throw them into a hamper. I never detect an odor since I've been doing it this way. Nothing really has a chance to get gross. At the end of the week, the wash is done and I have the next week's liners all clean.
Every week, all cage furniture is removed for cleaning. They are soaked, scrubbed, dried, and replaced.
Every three weeks the rats are transferred to temporary holding containers and their cages are broken down. I use a concrete mixing tub filled with hot water, vinegar, and dish soap along with a scrub brush to clean everything thoroughly. The cage parts are toweled off and reassembled. Cage liners down, accessories reinstalled, etc.
Maybe it's excessive but it's also effective. Nineteen rats and six mice in one room and no smell. I also use a germ guardian mini air purifier. I find this is really effective, especially with the musky mouse smell.