How to reseed dead live rock?

[mark]

I grabbed a piece from a garage sell, people said in was on a shelf for years. After a good scrub, rinse drying in the sun, just put it in the tank and now after about 3 weeks it getting some coralline growth. Same idea as base rock from the LFS, things will move over.

The only concern I have was it clean enough before I put in in the tank, were the people smokers, did they Pledge the shelf and overspray the rock etc? Might be something to consider.