How to have flashlight toggle on sharp shake motion with Tasker?

I would like to toggle the flashlight when shaking the phone sharply. I have tried setting the Tasker profile to shake left-right + display state on + not proximity sensor. This still is very buggy. For example, while riding on the bus and using my phone the flashlight continuously turns on and off. Any better ideas? Is there a way to make it two shakes, back to back?