Opening is easier than tightening...
The only thing that will improve pocketing skills is discipline. Tightening the pockets is compensation for a weak mind. This is something that a lot of people misunderstand, when thinking about a practice table.
Tight pockets hinder your ability to practice hundreds of different shots. Think of it this way: you can always tighten up your aim, with a bit of additional focus. But, tight pockets tend to keep you from firing balls in, and moving the cueball multiple rails.
