In reply to ADJC: I live and work around Fort William.
Different people swear by different products- both natural and artificial. I suspect the concentration and regularity with which they are applied, the variability of midge levels and the mixture with different levels of perspiration make them hard to compare.
Skin So Soft is an oily product that sits on the surface of the skin if you don't rub it in and acts as a barrier (not rubbing it in is important that's why the spray on stuff is better than the lotion). In the same way you could use baby oil or vegetable oil if you chose. None of them are chemically repelling the midges but watching them drown on your skin is quite satisfying.
Nothing is as effective as direct sunlight (can be a little short of that round here) and 5mph or more of breeze (that's quite common). So avoid shadey, sheltered damp locations, buy a midge net and experiment with the product of your choice!
Al