I wash everything and will start adding the statement right away. Sometimes when i hear about people not washing everything, I wondered if i was doing too much. It would be gross not to so ill keep washing!
When I hear about people not washing I think about all the germs, bacteria, and possible bed bugs they're dragging into their house. I know some folks don't care, but I can't imagine being okay with USED items all over my house and touching my stuff without being cleaned.
I send all my plush without tags through the washer. On my listings I put "gently washed with unscented detergent". For the ones with tags I surface clean them and put "gently surface cleaned with unscented detergent". I used unscented detergent in case of fragrance allergies for whoever may purchase.