I agree with the milk weeds, or yarn that steelheaders use. The powder may lead you astray if you are in a tree. You will be amazed and learn a lot about wind currents using something you can see for 20 or 30 seconds, up, down 180 degree shifts. Put mine in a plastic film can with a hole drilled in the top. Learned this from G Fred bout 20 yrs. ago.

I use a 20 yd piece of dental floss tied to my upper bow limb. That way I know the wind direction and the outer edge of my shooting range.