Onions cure ear infections?

I have heard this from a couple of people, and I have never tried it for myself, so I'd like to know if this is true:
When you have an ear infection, take a fresh onion, cut it in half, microwave it until it steams, then wrap it in a towel, tilt your head so the infected ear is up, then put the steaming onion over the ear. It's supposed to draw out the infection.