Yeah, you still can but what is important is making sure you do mean it, and do mean it actually. Substances are very unnecessary and I'm sure you don't need to be told they are also very damaging in multiple ways. You'll have to quit doing them if you want to empower and advance any decent amount. If you don't, then don't blame the meditations, the JoS, Satan, the Gods and Goddesses... You'd have only yourself to blame.
Which is your master - substances or yourself? Don't try and say "myself, so I can drink and smoke as I want and do meditations" because then you'd have decided already that substances are your master, plus you won't get very far. I should also mention that succumbing to substances means that the jew is your master - if it weren't for the jew, we'd be very empowered and advanced already. The jew uses any means to stop you from meditating, empowering and advancing. Let me ask you - are you a slave? A bitch? You must decide.