humu,
IMHO, using fresh water, high salinity water, carbonated water are all terrible ways to get unwanted critters out of your live rock.
They work great, but also damage the good stuff you paid all of the money for. My suggestion is to trap any unwanted critters during curing.
Mantis shrimp and unwanted crabs will be attracted to baited traps. The true anenome/gorgonian eating fire worm only comes from the carribbean, so if your rock is indo, you don't have to worry about them (they theoretically could get introduced later from another tank, but it is unlikely).
The only thing left to worry about is the snail eating worm, and they are generally easily trapped at night when they are out hunting. There are a few other undesireables, but they are extremely rare.
So, relax, check out your rock with a flashlight at night as it cures, build a soda bottle trap, and know you are preserving lots of good critters by not being overly agressive.
HTH,
Adam