I don't think a time based rate would work - however I like the idea of incentives to promote faster play.
How about an early morning period for the golfers who just have time for a quickie - assuming they are familiar with the course. Let's call it "Fast track".
Golfers playing "Fast Track" will get a reduced green fee if they're Green Fee players or free cup of coffee if they're members. Of course the real incentive is for the players themselves getting their golf quickie.
However to get the reduction one has to sign up to the following.
1. Match Play scoring (not stroke play)
2. Only 1/2 set of clubs which must be carried.
3. No practise swings
4. No discussion of strategy when you are "on the ball"
5. Immediate "provisonal ball" if first ball suspect.
6. Only the player looks for his "lost ball" and it's limited to 3 minutes.
7. No distance consulting (eye-ball it)
8. No lining up of putts in 2 directions
9. All putts under 1 yard are conceded
10. No lighting up cigars on the green
11. No score card marking on the green
12. No anecdotes on the tee
13. No peeing in the bushes
I could go on - but I'll probably run out of takers