How to QT Rocks?

Ok so i got some huge flat rocks and I'm wanting to know how to quarantine them. Any advice?

Set them out in the sun for a few days and rinse them off well, that's all you need to do

So if I got them from outside then all i have to do is rinse them off? Maybe I should rinse them off and set them outside again and rinse them off again and put them in my tank? My brother in law got them from his friend who's dad gave them to him from the Guadalupe river. So they say!

Sound neat. I always rinse in tank water or conditioned water not tap water.

Well I was going to sell my 29 gallon tank but decided to keep it as a quarantine tank. These rocks are nice and my brother in law is going to break them in smaller pieces so they can be spread out through my other 3 tanks. I decided to keep my 5 gallon hex tank as a hospital tank since I don't have very many fish and they all are fairly small (all under 2").

Do a PH test on them; pour a bit of vinegar on them and if the fizz they will raise your PH, if they don't they are most likely inert and will not change your PH