Why does nose grease knock down the head on beer and soda? Freshman year, my first semester, I was taught many things.  One important trick I learned was when I was passed a beer in a 12 oz. plastic cup, I could eliminate the fresh foamy head by wiping my nose and touching it to the top of the foam.

I thought to do this recently with soda (as it seems soda head is more persistent).  The trick works there too.

What is the chemistry behind this?  Is it the salinity?  Could I use something less revolting than nose grease to do the same trick?
Any oil should work. 

Naturally occurring surfactants, such as lecithin, make bubbles or foam because one end of the detergent molecule is hydrophilic while the opposing end is hydrophobic (not rabietic, though). Without oil, the hydrophobic end prefers air to water, encapsulating the air. With oil added, though, the water-repellent end is attracted to the oil, forming micelles, instead.

You could put vegetable oil or mineral oil on your finger, but then the server might wonder why you stick your finger in the beer.

You might also try making a beer-powered boat! Tell your server, and ask for a free beer to prove that this works.