rubbermaid tub, tank, it doesn't matter. What does matter is: skimmer, powerheads, heater, and water changes. All done in ro/di water.
The purpose is to get the rocks cleaned of all undesirable dead stuff. This can take sometime depending on how much dead matter is on the rock.
You test for ammonia, nitrites, and trates.... Once all the numbers are 0,0, and as close to 0 on the trates you are ready to go.....