I bought some live rock too with them on there not knowing what they were at the time and the kid at the LFS never told me they were bad. I heard the lemon juice works if you inject it and I read online that Peppermint shrimp ( I would imagine they only go after the lil ones), and there's a sea hair ( I forget which one) that remove them as well. They do retract into rocks if something touches it so Idk how well running hot water would kill them unless it sat in boiling water for a while then I guess it would. I would recommend checking out Bulkreefsupply.com for rock. They have dry live rock with nothing on them and cheapest place I ve found it so far.