that isnt true. this is a completly different species of anemone than the ones you have. not only will it not host clowns (and clowns ill not host it), but it stays that size and delivers a powerful sting to corals and fish.
clawlan: it is considered a pest anem if they popular quickly and deliver a strong sting. They can often pretty much take over a tank until your fish cannot even touch the live rock in time in the right conditions.
