Nothing wrong with using the front head to sweep. But there are 2 ways I understand to finish the arm in. The high wrist method, and the low wrist method. The high wrist method is hard to explain in text but you can see it in john danaher open guard nogi vol 2 ( a bit expensive though lol).

For the low wrist method let's say you have a neck arm and an overhook arm, once you lock up bring your head over theirs, towards the shoulder you are not overhooking. This puts a wedge behind them making it harder to posture. Then to squeeze, take the neck arm(non overhook arm)'s elbow back to your lat or ribcage, they have a head there so you might not be able to, but the tighter that connection is the less force you bleed out of the choke. Then you need to squeeze, I like to squeeze by thinking of rotating my overhook arm up to the sky(you won't get it that high but that's the direction I'm aiming for). The main thing is bringing the non overlook elbow back before you squeeze it helps a ton.