Well, if you look at this chart
http://lib.store.yahoo.net/lib/marin...mbioticMap.htm
it looks like both the False Percula and the Percula do not host in BTA's. It really pays to check out which anemone will host which clown. I can't explain the behavior of "ripping your anemone to shreds," but you have two choices, remove the anemone or remove the clowns.
As to telling the difference between the two species of clowns, I can't help you there either. I've stuck with Tomato and Maroon clowns. Both species do host in BTA's. Be aware that Maroons, though very hardy and beautiful, are THE most aggressive of the clowns. I've been bitten by my female (about 5") and she's drawn blood!!!!