Hello again,
Here's a small update.
First to recap, i was using a 3 Ohms, 50 watt power resistor (aluminum case) under the freezer cage to defrost the freezer, running the resistor at only 27 watts (9 volts). It works exceptionally well, but i realized that one side does not get defrosted as well as the other side (the compartment has a metal bottom and two metal sides and everything else is plastic). Looking into this, i realized that the side that did not defrost as well has a big gap in the bottom section where apparently the air is allowed to circulate so that the refrigerator compartment gets cold but not as cold as inside the freezer compartment itself. So they designed it with a big gaping slot on one side where that side meets the bottom metal part. The problem was, the resistor on the bottom of the cage provides enough heat to defrost the bottom and the one side but it does that one side pretty good because there is plenty of heat conduction from bottom (the resistor heats the bottom) to that one side. The other side has almost no conduction thus it doesnt defrost well on that other side.
The solution which may be the only solution was to mount a second resistor on that one troublesome side. A second resistor mounted about 1 inch up from the bottom of the side seems to do the trick. I had quite a bit of frost buildup this evening and the two resistors working together freed all of the ice. There was more than usual because it built up on that one side so after about 10 minutes the ice came loose and was easily removable. This wont normally be the case, but at least now with the two resistors that one side will not be able to build up over a few days now so it should work much better. I suspected it was going to take at least two resistors but was trying one first just to see how it went.
So the bottom line is if the sides of your freezer are connected with metal and no gaps then one resistor on the bottom in the center will probably work ok, but if there are gaps in the metal between the bottom and sides then the sides need a separate resistor. Mine had one side connected completely (like one piece of metal) while the other side had a big gap, so i needed two resistors.
One more little note:
I was worried about electrolysis eating up the freezer metal if there was any leakage current getting from the resistors to the metal, so i decided to use AC rather than DC. DC will carry the atoms away from the metal and eat up some of the metal. But i also realized that AC will remove some of the atoms and then try to put some back, which will also appear like some sort of rust process in the metal, so it may not matter if we use DC or AC because the resistors have to be mounted so that the bare leads dont touch the freezer metal and also with some silicone to insulate the terminals.
If anyone reading this tries this with their refrigerator or freezer i'd like to hear about it too.