Smoking pot and becoming a police officer

Theoretically let's say you've occasionally smoked pot before, but want to become a cop. I know they have some polygraph questions that ask about what, if any, illegal activity you've been engaged in when applying.

I guess pretty much you should quit doing shit like that for the better part of 12 months before taking that poly? I'm assuming there's 0 chance of being honest and still getting accepted. Assuming all other areas of your application are stellar.

I feel like this is a pretty accurate chain of thought?