I remember reading about this a couple of years ago TTT but I'm not sure I would have the energy or time to to go through with it. I prefer a loud whistle down the phone. My husband does the time wasting tactic!
The TPS is completely useless. Most companies just ignore it and treat it as a irrelevance. Other companies are calling from abroad and aren't even aware that it exists but would ignore it anyway.
The cold calling situation has got so bad that I took my home phone "off the hook nearly 2 years ago. Everybody that needs to know either Text me, email me or call my Mobile. Having a iphone helps this process.