Dipping live rock
 

Hey just got a bunch of liverock from a fellow reefer that been in his sump for years. Looks clean. Should I just toss it right into my tank or can I use revive dip on it too?

Diping stuns not kils well on ocation it kills but normaly it stuns and things get stuck in the rock then recover

If you want the healthy fauna of his 'live' rock, then don't dip it... Live rock is just that, alive with countless micro fauna, dipping it could cause die-off and then huge ammonia/etc leaching :(

You could sorta-quarantine it if you had another tank that didn't have any fish/rock/etc/etc in it (say a dedicated tank for water changes/etc) -- but you'd really only be quarantining for the larger-critters (evil crabs, mantis shrimp, etc), the micro fauna will find it's way into the water column no matter where the rock is put.

I have on 2 occasions taken live rock from tanks that I trusted to not have really bad things in it -- but it's still a risk.

If it were me, I'd shake the crap out of it in a bucket to catch/save all the iso/amphi/copepods I could and put them straight into my system

Then I'd put the new LR in a tub or bucket with a heater, powerhead and a loose lid (to block light only, not airflow) for weeks while I looked it over for crabs, mojano, aiptasia; monitor it for phosphates and algae; the list goes on

Too late I just tossed it all in the sump =)

Rock that's been sitting in a sump for years should have been tossed in the garbage, not your tank.
Greg gave you the best advice if you wanted to actually use it. Although I'm not sure why you got more rock just to add it to your sump.

Curious to why you would say this. I am just setting up my first tank and I was planning to put some rock in my sump so if I do set up another tank, I have a clean source for live rock. Is this a bad idea?

Why the garbage??

Rock that is old, especially from a low flow area such as a sump, IMO will be full of crud (PO4). I just removed 3 yo rock from my tank from a high flow area and it was full of crap.
Also, I have to question why the addition of rock is warranted? What purpose does it serve, other than trapping detritus in the sump? Was additional denitrification needed? How was this determined?
Simply adding more rock for the sake of adding more rock seems pointless. More is not better.

So, when you remove rock from your system do you cook it and replace or do you purchase new "fresh" rock to replace?