How long should I boil live rock for?

[ALang]

+^^!!
Unless you are able to do it in your tank, with no lives stocks, none.

You need to closely monitor your tank's parameters the next few weeks, even couple of months. I wouldn't put any of your good live rocks in there with the boiled ones yet, until most of the nitrates, etc, have been leached out and testings shows that they are near or close to finishing the cycle.

Good luck.