It means just what it says. Find a Crock Pot that you can use for cleaning the motor, because once you've used it for this you'll never be able to cook food in it again. You'll need to get antifreeze, although it doesn't necessarily need to be Prestone but it does need to be "the green stuff". Disassemble the motor and make sure you get out all of the rubber and paper gaskets, also remove the glow plug. Place the parts in the bottom of the Crock Pot and cover them with a couple of inches of the antifreeze. Put the Crock Pot on low and let them heat in the antifreeze. How long they need to be in there depends on how much "gunk" is on the engine. Using a pair of tongs take out the parts every hour or so and use an old toothbrush (once again, never use it for brushing your teeth again) and see if you can brush the gunk off. When you can brush it off it's been in there long enough and you don't have to keep cooking it. It can take anywhere from a couple of hours to 12 or more. Now for the important tip. DO NOT HEAT THIS INSIDE OF YOU HOUSE OR INDOORS. DO THIS OUTSIDE IN AN AREA WITH GOOD VENTILATION. DO NOT BREATH THE FUMES, THEY ARE TOXIC AND THEY CAN KILL YOU.

With that said, why do you need to clean the engine off?? The "brown crud" you mentioned doesn't hurt anything and the motor runs just fine with it on there. Unless you are 100% sure of what you are doing with the crock pot and antifreeze I wouldn't recommend doing it. They really can be a lethal combination. I'd just leave it on the engine and fly it like that!!

Ken