I haven't used foot powder for many years. For itchy anti bacterial and anti fungal actions washing with a medicated soap such as Tea Tree or Bog Myrtle works well.

http://www.amazon.co.uk/Health-Aid-Tea-T...089&sr=8-10

There are foot powders around that use Tea tree oil as the active ingredient rather than the menthol and zinc oxide for the Gold Bond.

http://www.amazon.co.uk/Thursday-Plantat...1732&sr=1-2

Good socks are very important as well and I find that a Mixed Synthetic Wool with Silver technology works very well if a change of socks out in the wilderness is difficult.

http://www.marksandspencer.com/Blend-Bli...;qid=1345761346

Keeping you feet dry out in the wild can sometimes be a challenge. Goretex Socks can be very handy. Never go barefoot in any location of your local Gym. Prevention is better than the cure.

If Gold Bond works doesn't work for you then you would have only lost around $10 finding out.