The concept is to allow for no more input Craig, so away from bioload. I put thm in a dark drum so thier is no more input from photosynthisis also, then just a power head and a heater to keep the bacteria and other critters alive.
Picture you rock as a huge apartment building for bacteria, never mind the larger critters that may live in thier. In order to consume or reduce products bacteria create enymes, they also reproduce, and die off and shed thier shells,this along with other this they do is what I am refering to as bacterial action or Tugor. With all of these actions they increase the biomass with in the LR. Because the LR is limited for over all space the end product this the accumulation of these products shed from the surfaces of the rock. In a normal tank enviroment all of these things are happening,but thier ia also a constant influx of food sources from the tank itself. The rock houses all the critters that are capable of reducing the nitrogen based products that enter it, but are restricted to the ammount they can do due to the population constrants do to the surface area of the rock. So its a loosing battle for the rock and pores and pathways get clogged with detritus and organics, when this happens it skews the enviroment with in the rock and turns it to more of an anaerobic enviro. Which means the rock begins to loose its ability to perform nitrification. The time factor is all based on husbandry and bioload.
When you place the rock say in a garbage can with no light and no outside food sources, you are forcing the rock to feed on what it has stored and clogged with in it, while all the time sheding the detritus or end product. The longer you leave it the more of this organic material will be consumed. the end result is that the LR will open up and unclogg it pathways and skelital features and thus allow for more surface areas for bacteria to grow and more open pathways for the food and various products to filter through the rock.
Oh and yes I use a PH, heater and I do water changes on it, I even run a skimmer on it to
Mike