Amazon has the 6-oz SILKA Odor Fighting Foot Powder for $6.28 - 25% off coupon (check "Save an extra" box, eligible on first S&S order for this product) - 5% off with Subscribe & Save (can cancel at any time) = $4.39 with free shipping on $25+ or with Prime.

Specially formulated with Talc and Zea mays (Corn) starch.