I've read that its also great for treating tooth aches on the trail.
Also, cut and pasted from wikipedia:
"Tincture of benzoin has two main medical uses: as a treatment for damaged skin and as an inhalant.
It is often applied to skin before applying tape or other adhesive bandages. To some degree, it protects the skin from allergy to the adhesive in the tape or bandage, but mostly it makes the tape or bandages adhere much longer. It is also used by athletes for its reputation of toughening skin exposed to the tincture.
It can be applied to minor cuts as a styptic and antiseptic (an effect of both the benzoin and its alcohol solvent).
It is also used as an oral mucosal protectant, for recurring canker sores, fever blisters, and the like.
It can also be inhaled in steam as a treatment for various conditions including bronchitis and colds. There is some disagreement as to whether or not benzoin should be used as a treatment for asthma.
It is used in the U.S. military to treat blisters. A common treatment utilized by medics in the U.S. Army is to drain the fluid from a blister and to inject the same amount of compound tincture of benzoin, to help seal the space created by the blister, to serve as a local antiseptic, and to prevent further abrasion or loss of skin. This is commonly known as a hot shot amongst military personnel due to the burning sensation experienced. An older and ill advised method of the same name involves identical procedures using bleach as a substitute for tincture."