[BABY'S MOM]

I sanitize my cages every day. But for a normal person, once a week should be fine.

To sanitize fleece - I wash all fleece, and towels in unscented laundry soap, with 1 cup bleach (hot water in washing machine).

To sanitize cage - I wash bottom of cage with HOT, soapy water. Rinse out really well. Then run a 1/4 cup vinegar, and 1/4 hot water around , and then rinse out bottom of cage again. And you're done.

You might want to ask another piggy mom for advice on what they do, because I am a clean NUT.
But hope this helps, and again, in time you'll find your own cleaning routine!