While I am sure that this would work better then nothing, paracord is way too thin and will cause significant damage. I have use a triangular bandage as a tourniquet using a similar technique quite effectively. A cut up a shirt or other piece of clothing before using a piece of paracord.
I have never felt that I needed a fancy tourniquet either. The chance of me needing one is so low that I am willing to go with a piece of paracord and a pen. I can tie the ends of the paracord together in about five seconds and use a pen or something similar as a windlass to tighten it up. I know it is not ideal but it is better than letting someone, especially me, bleed to death before someone more competent and presumably better equipped is able to help.