I have never know them to furnish a beach bag. What I do is I get a large bag (get them "cheap" at the thrift store), if you don't want to pay a big price.
If necessary I will clean them out, but generally their not that dirty. I take them on the airplane with me. I put my purse/cosmetics/medicines, and a change of clothes in them. When I get to my room, I take it all out, and when I go to the beach, I put my tanning lotion/towels/food, etc. in it instead.