The 'COLD HEAT' soldering iron works on the tiny amount of current needed to heat the element at the end of the device. Look closely at the end of the tip.
It has a divide down the middle. Both sides of the tip must touch a conductor.
The current flowing through the conductor will cause it to heat very quickly.
On the Top of the device is an LED that should turn RED when the tip is in contact with a good conductor. AS the heat builds you can then add solder.
On the TV ad they show people (ZAPPING) things together. In fact that is a BAD thing to do because the solder and metal have not had a chance to 'FLOW' and as a result you will get a cold solder joint. Leave the device ON the part for a moment and then add the solder. Just like you would with a normal soldering iron.
The tip REALLY DOES cool down as fast as they say. So I do like using mine.
I have a few butane irons I have used also but the heat from the flame on the side of the units melt and burn nearby parts. The "COLD HEAT' unit has some good uses but it is not a universal tool.
Important tip. Never heat the SOLDER. as the solder melts the electrical contact will break and it will be hard to keep the heat flowing. Remember it cools down VERY fast. Heat the PART then add the solder to the PART not the tip.
Let me know if that helps.