You need to learn the "drop" the club/arms/hands back "down the wall" before you use your pivot to swing "left of the wall."
Watch Never Hook Again if you have it.
It is very important to know that "Up The Wall" is a FEELING.
Your club doesn't make it. It goes in.
But...It mentally gives you the IDEA that you need to LIFT your arms to make a good backswing. You do. You also need to pivot.
What about the inside of the ball?
Like Jim said, the DROP takes care of that, but some folks just CAN'T drop.
To DROP you have to GIVE UP CONTROL and do NOTHING. Lots of folks NEED to do SOMETHING.
So....
"Shake the sugar."