Fixing the slice

I understand that the in-to-out swing (and square club face) is the key to getting rid of the slice, but no matter how many drills I do (trying not to hit alignment sticks or head covers), strengthen my grip, close the club head then rotate forearms, try to push the club head to the right, left shoulder higher than right…….any full swing I take has a bad slice. Clearly out to in.

I’ll post a swing video this week but my question to those who fixed their slice: was there a drill that worked? A particular adjustment? Or was it just many many many sessions and slow improvement?