I know anemones in general, and more specifically BTA's can get picky about where they bury their foot. I mentioned this to subliminal or clown-lover the other day in a thread, you can take a look at haitain live rock. A lot of the rock from Haiti is shaped like donuts and has a large hole in the middle for anemones to rest in. The waters off Haiti are known to be well populated with Haitain rock anemones, tons of them and the rocks that are harvested from those waters are often found with center holes like donuts. I like their shape, I personally have three such rocks in my tank.
They are not too large, max weight about 1-2 pounds. I have an LFS nearby that is constantly getting them in.
Anyways, just a thought, they make great homes for anemones! My rehabing BTA hasn't moved from that rock since the day I got her, she loves it. I will try and snap a pic tonight.