Will it kill all crustaceans? Like pods? And shrimp? There are 1-2 shrimp hitchhikers in there that I was maybe going to keep for the fuge, but probably not haha. But I def. don't want to kill any pods. One of the reason I got the ocean rock.
Interceptor will make a decent dent in pods population and can stress/kill shrimp. You can try a fresh water dip to get the crabs to bail out but that will kill alot of "desired" hitchhikers.
On a sidenote, I will always use dry/base rock on new setups after my initial 125 setup and fishless cycle with pure ammonia. There are MANY bad things that hitchhike that can sit dormant or unseen for a long time that seem to come out of nowhere to cause probles . The use of only dry rock I am sure is highly contested, and I will not argue for it so no need for anyone to try, there are always positives and negative to every method.