How Do I Clean My Characters?
It's been my experience that items made with synthetic yarn and synthetic fiber fill can be washed by hand. If the item has become extremely soiled, it may be worth trying it in the washing machine on a gentle or hand wash cycle. You may want to remove sewed-on items if you feel they are vulnerable. I like drying in a dryer because the item is less likely to get musty, but if you judge your item to be too fragile, drying in the sun should also work. The important thing is not to let it stay damp for any longer than absolutely necessary.

If you have a handheld steam cleaner, you could try that too, especially if you have stubborn stains. I've used mine with vinegar mixed into the water to successfully clean cushions soiled with urine, but I've never used it on a hand-knitted stuffed character. Still, it's another option you could consider experimenting with.