You would most likely have more die off from all live rock but I still think dosing the tank with either pure ammonia or a dead shrimp will be needed. The time frame would most likely be the same. A couple days to a couple weeks. No sure way to know.
Now if you got all live rock from a tank breakdown from an established tank i would think you'd see a small spike of ammonia and then ypou wpuld be set to go. It's all alot of variables though....The live rock at your lfs
is probably not fully cured as it comes in frequently.