They are fairly hardy, but care must also be taken when considering water parameters. I have quite a few yumas and floridas in my clown breeding tank which has no skimmer~fairly dirty water for a 12gal. The rics have taken over alot of the surfaces in only a couple months. In my very-low-nutrient (VLN) SPS dominant system, the rics have been stalemate for the last year. So I disagree with pbmatthews and feel the success of my rics in the Black Onyx Clown breeding tank is excess particulate matter, slightly elevated nitrate level & maybe the occassionaly fry that hatches prematurely.
As for the blender comment, there is NO WAY a ric will survive a blender. Most shrooms would survive a blender and create complete chaos in a non-softy tank if you dumped in the contents of the blender. Rics are MUCH more delicate as I have doomed many rics when trying to propogate them by the slicing method.
If you want a truly indestructible coral, I can ship you some zoas if you pay the USPS Priority shipping. Honestly these bad boys have sat in a bucket of SW with some ambient light from a standard CF next to the bucket for over a month, been buried in the sand (= no light), tolerated room temp water (~68F) & fully-recovered from a kalk soaking overnight. These polyps WILL NOT relinquish their footing on one of my favorite pieces of LR. The next method of removal will be just letting the rock sit outside for a month to dry out. I can gather all these up any send your way if you want bullet-proof.