Me too - scoop as required (usually twice daily, it depends on the weather) and try to completely empty/clean weekly.
Don't know if anyone else does this, but once I've emptied mine I usually wash it out in the bath using the shower hose - I can get the whole thing, including cover, with really hot water. I do this every couple of months maybe - on a weekly basis I just give the tray and inside of the cover a wipe down with some white vinegar..