Answers. Best Answer: Depends if you are a habitual user(smoke everyday), then it could take up to 30 days to get clean. If you smoke more sporadically (once in while/ weekends etc) then it could take a week.Drink plenty of water and do cardio sweat it out. You can also buy drug tests that test for only marijuana online.nswers. Best Answer: Depends if you are a habitual user(smoke everyday), then it could take up to 30 days to get clean. If you smoke more sporadically (once in while/ weekends etc) then it could take a week.