Spotted theses today, mesh laundry bags either conventional flat shape or round tub shape. With zips . Just the thing for fleece washing I was thinking so I bought some.
Spin drying washed fleece or yarn I do by putting it into a pillowcase leaving enough slack to knot the end . Seems to work ok. I have a couple of very old poly cotton pillowcases that are mostly poly and not much cotton that I keep for this.