couple of rock cooking/curing questions.

so i finally purchased a full 75gallon drilled tank/sump, stand.. the whole shabang.

this purchase came with 50lb of liverock from the carribean. i notice alot of these rocks have coral skeletons on them, various sps plating corals.

i setup the 50lb of rock in a rubbermaid container, and added my addition dry live rock that i had taken out of my dt awhile ago. so today the water smelled like cat urine so im assuming the water is just choc full of ammonia.

my questions that im unsure of are.

how many "dunk buckets" should i set up to dunk and do water changes? i bought another rubbermaid that i will fill 1/2 way full of fresh Instant Ocean salt and i figured 3 buckets enough inbetween? or could i just blast each individual rock with a powerhead, use 1 dunk bucket, then straight into new rubbermaid?

my other question, i plan on using instant ocean to cook/cure rock. once the process is complete if i add the rock to a tank using a different salt (aquavitro) will there be mass die off from the rapid change?

thanks! btw i dont use a heater, my maxjet 1200 keeps the water actually around 79 degrees go figure. very hot pump.