If i get a thousand they are divided into 3 containers, clean them fairly regularly, or at the least take out a tube, shake all crix off, bin it and replace [with all of them one at a time] and ofcourse keep veg fresh and bran topped up, but atleast once a week a full clean out and dissinfect.
Just get a big carrier bag with no holes in it and shake all the crix in there, grab whats left [usually takes longer than the rest combined]
clean and then put new tubes in and fresh food etc and put them back.
The hardest part fo rme is getting them from that poxy fabric bag thingy to the tubs, as the egg cartons they come with are toooooo damn big to put straight in the containers, and the amount of shit in there to begin with...eeeew.
I just shake the shit out of the cartons from within the bag [closed] and take them out one at a time leaving just all the loose crix plus a hole loada crap and scoop them up by hand and sort them into containers that i have ready open [and tube filled plus food and veg] as i go.
I got in a right mess the first umteen times i tried this but have it sussed now lol...nightmare...the horror i felt first time i realised my "bulk" crix werent gona come conveniently packaged....