I tried shooting a southestern indian two fletched arrow several years ago. ( Hence the name "2fletch".) I was using primitive shafting at the time including rivercane and also dog fennel.
The dog fennel was a surprise. It's really a weed, but when it's properly dried out, works well. I once shoot a whole 3-D tournament with the same arrow of dog fennel and natural turkey feather that was 2 fletched.
It seemed like though most of the shafts flew well with the 2 fletch, some of them would not. With a fletching jig though, I believe that the results would be more consistant.