I use white vinegar in the litter trays (as it's the only thing I find that will shift the stains from the plastic), my rabbits are pretty clean so most weeks I just sweep out the dirty stuff from the hutch and put in new stuff. Occassionally I will clean with an animal disinfectant but not every week. I don't know what other people will think of this as I know some scrub their hutches all the time?
With the runs, again I sweep them out every couple of days, then occassionally I move everything and get the pressure washer out - just use water with that but it's so powerful it shifts everything (including a bit of patio I'm sure).
Hannah