unicorn spawn points and incense

has anyone had experience camping a rare spawn point with incense?
did you get much out of it?

I know a spawn point that is relatively reliable spawn larvitar (if i spend ~90 minutes walking around i get one at the same spot ~ 1/2 the time) and as incense draws from the local spawn pool it might get a good yield.

as an aside those suckers aren't always easy to see.