Sinus drainage?

Have you or know someone that had one or all of their sinuses drained? how did it feel, what was the recovery time, was anesthesia used, was it performed with suction or was it invasive? the reason i ask is because i always feel congested and last week i went to the dentist and while leaning back in the chair i choked on my mucous several times as it dripped in the back of my throat.