Quick rock curing

[mattr]

So I had some rocks in my fuge and I decided to add them into my display tank. The issue is that I forgot that I have a emerald crab in my fuge. He now has no place to hide, and is managing to crawl all over the place up and down baffles.

I have some dry rock and I have been boiling in water for the last few hours to "clean" it... how horrible would it be if I put it in my fuge? I have a 50g display tank with 20g in the fuge.

Thanks in advance for any help