"Holding on" will keep you from applying Maximum #1 pressure. That's the way that I thought of clubhead lag for years. In fact, that's what I was taught.
You can quote me on this:
"LAG PRESSURE IS CREATED, NOT SOMETING THAT YOU TRY TO KEEP"
You really have to learn to DRIVE the #1 pressure point. I've given this advice a number of times, but it really works for most:
Place a penny in between the #1 pressure point and the left thumb. Try to keep the pressure applied against the penny during the whole swing(hit). Make the #1 the direct drive and allow the #3 to recieve the indirect pressure. MANY try to make #3 the direct drive, and in the end, flatten the right wrist.
I wish someone would have told me that years ago. I used to try to feel #3 and try and drive it. Results were terrible. I gave up on hitting and stayed with swinging which when recently viewed it appeared a mixed mess.
Actually I don't believe I ever really felt #3 correctly till Yoda had me do some drills. Once felt, Once learn, I definitely focus on #1 when setting up to do a hit.
That penny drill should do the trick, simple but really effective.