Can't sleep while counting

I can't get to sleep while counting in order to WILD. I just lay there, counting and counting and counting, but nothing happens for up to 20 minutes. Am I just impatient, and should count longer? Or should I try a different way than counting? I'm pretty decent at keeping my mind on counting, though I do sometimes start dirfting off thinking about something else. When I do, I always remember to count again.

Depends if you usually sleep quickly or not. I think the counting method is for people who lose consciousness too fast : counting force their mind to stay aware, and thus stay lucid. For you, it just keeps you awake.
Maybe you should explore techniques that suit you better (for example, just focusing on your breathing)