[incoma]

The entire point of the string is to manipulate the rubber around the channel. You won't want something too big that it doesn't easily move, and you don't want something so small that it rips or tears the rubber. I used string for fence posts like boilrman. It worked well on the front window, but tore the gasket on the back window. Perhaps I got too rough with it..?? Good luck, it's not the easiest of projects. Having someone help you is key also.