How much are you talking? A larger amount of pieces I would rinse out all the “dust and Dirt” with some RO and after a water change sink it into a container of that water for awhile before adding. A smaller piece could probably get away with the rinse with RO and then a rinse with water change water then put in. But that’s all just me. I added a decent size piece of dry rock to my tank a month ago and all I did was rinse it with the RO. But I have a 180 so that’s not as big of a change in comparison.