I do know that most fabric store fabric doesnot hold up well to UV. We tried replaceing a avaition grade wind sock with fabric store home made, it lost the dayglow color in a month and was shredded in 3.

I've go three socks with trailing streamers off ebay for 3 bucks each. They've held out for 6 months before they go bad.

http://cgi.ebay.com/SET-OF-2-60-AMER...3A1%7C294%3A50

The big bucks for an aviation grade sock is well worth it they hold up.

We use a 10 foot pole with another 2 feet of music wire at the top, right BEHIND our pilot stations. Since you're not supposed to fly there, then there's no chance of hitting the pole.
Our swivvle is a fishing leader snap trapped between to wheel collars on the music wire top.