Spoof,

Trying to 'reverse' the thread direction so you can use a tool that doesn't work properly for your tying isn't a good idea.

If you can't get the Thompson to work for you, for whatever reason, get a tool that does work for you.

Try bending/modifying the Thompson. If that doens't work, go to a fly shop and try a different one.

Make one that works for you. You can get stainless steel wire rod at any hobby shop, or stainless welding wire is available at any welders supply. A pair of pliers, a file, duct tape for a handle and some time is all it takes. (Practice making the shape with old coat hangers until you find the one that works).

The first whip finish tool I ever saw was simple loop of light dacron tied onto the end of a short piece of 1/8 inch dowel. You layed the loop onto the fly, wrapped the thread over it, place the tag end of the thread through the loop, and pulled it through. Works with either hand. If I was making one today, I'd use gel spun for the loop because it's slicker.

Buddy