In my opinion, it's not the actual lock itself that is the problem, so squirting some de-icer into it really isn't gonna do anything. Correct me if I'm wrong, but when you use both the keyfob OR the key to lock/unlock the door, they all do actually lock or unluck?!?!When you use the door handle to actually open the door though, the cable that is attached to the handle, which 'activates' the locking mechanism itself is froze up and doesn't function in the proper manner. So to resolve the issue, something has to be corrected with that cable. Unfortunately, I don't know the exact answer to it, as I've just been living with it on my truck.
Your best bet is to contact your dealer and try to order the parts that get replaced with the TSB. I'm leaving for lunch now, but I'll try and dig up some #'s for you when I get back.