I always keep a tub of that **** in my jeep. I have never used it on my face on cold days, even though I have though of it. On longer sessions I always use it on the neck, arm pits and crotch of my wet suit to prevent chafing. It works pretty good! It also stays on your skin for a while. Has not ruined my wet suit as far as I can tell, but keeps it nice and slick. It is typically only needed because my wet suit is not new any more. The older the wet suit, the more chafing I seem to get.
By the Way, There has not been a surfable wave in N.H. in the last month, and its seriously depressing.
been doing it for a few years now. It seems to help me for sure with the cold water and the wind, wether it's just a mental thing or not who knows.. Just be sure to clean your face after the session.