I get them every month or so. The worst are the ones that are right on the gum line, brushing is like having a needle driven through your mouth. Others around the tongue make eating unpleasant.

Best way I've dealt with them has just been to sterilize them with anti-septic mouthwash. They go away pretty fast, though hurts like a bitch. Alternatively, you can rinse your mouth with salt water, though I've had little success with that.