By cleaning, I'm meaning a removal of all litter and a disinfectant clean and replacement with fresh litter. This is an enclosed tray for 1 cat's use.
I had anticipated doing this once every 3 weeks (litter packets says once a month). However utility room was starting to pong so I fully cleaned out the tray today and it is only 2 weeks since this was last done. The litter absolutely reeked. I can still smell it now in my nostrils. How often do you do a full clean?!