How can I clear the drain pipe on a Westinghouse refrigerator?

i have located the entrance of the drain pipe behind the wall of the freezer compartment, it had some food and gunk around the pipe but nothing that was directly blocking it. I poured some water down the pipe and it comes out of the temperature control unit in the fridge compartment. The drain at the end over the compressor is fixed and is difficult to get anything into it to try to unclog it (assuming that the clog is at that end of the pipe and not closer the entrance). Does anyone know what I can do? Is there is a good tool or something that I can get in there to unblock it? Additionally, if water was coming through the temperature control where the defrost timer is would this stop it working?