This is a different question, but what's the best way to make sure there aren't any predators like mantis shrimp and fireworms on your LR?
A hypersalinity dip. Get a container and fill it with saltwater of around a 1.040 specific gravity. Placing the rock in there for about 1-2 minutes will rid it of all mobile inverts. Then you can pick and chose which you want in your tank. It will leave sessile creatures on your rock though (like anemones, hyrdoids, etc). Be careful though, and don't put your bare hands in this bucket!
Even though it's somtimes reccomended, don't use a freshwater dip. It will not only kill the inverts, but it will kill all life on your rock, and you don't want that.
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