As of now, my ocellaris clowns host in my frogspawn. When I bought the frogspawn (about 9-12 months ago), it only had two heads and the clowns hosted in my torch with 6-7 heads. Now that the frogspawn has about 8 or 10 heads, the clowns prefer it.
Actually, I think the frogs, torches and hammers are easier to keep and are often in better condition from the average LFS, so they make a great substitute for anemones. The corals just have to be large enough and not be stressed by aggressive hosting. I guess I would not recommend LPS for hosting larger clowns, but small ocellaris arent as forceful IME. I went through 4 anemones (most getting through the 'anemone proof' powerhead when I was out of town), before I went with a host that I could epoxy to the rockwork.