I actually replace all the stuffing with new polyfill. When I wash and fix my primary plushies I put new filling in. I also put a lining for making them into a plushy space savers. Every six months. I try to clean and fix twice a year.
Of course mine are mostly 4 or 5 foot. Wich kind of require it. I keep one in my car between the two front seats. She keeps my reciepts and things.