Old sand and rock? Any issues?

[santeeeyyy]

I currently have my third tank, I was just wondering as of now I do not know what I want to do however, I do have some old rock and old sand, will it matter if I just clean it out with either the hose or RO water and then toss it in the water to cycle?

 

[Spare time]

I'd rinse the sand. As for the rock, what I have done is put it in a plastic bin with a heater turned up a little high and at a slightly lower salinity. Then I toss in some bacteria and let it go to town