Addiction and drug use aside, if ANY man ever manipulated me for sex by saying they would go to someone else if I didn't give in to their demands, they would be to the curb instantly. That is disrespectful and unacceptable in my book. I am not a toy or object to be used, I am a person to be loved and cared for......that goes for you too!
Clean in my book is 100% not using for an extended period of time, at minimum until at least the withdrawals and immediate physical cravings have passed. Maybe you can call it slightly 'sober' if he hasn't used for a couple of days, but I wouldn't call that clean.