The brain wash drill is putting all 15 balls on the table, none touching the rail or another ball and running them out without letting the cue ball touch a rail. It's a great way to work on finer CB control and strategy/planning out your run-out.
I do not time my practice anymore. I base my practice time on how productive the practice it being and how I am feeling. Some days I need less then a hour just to stay in tune and somedays I'm at the table for 3 hours or more. At table means at the table and not at the pool room.
It all depends on if I fee the practice is being productive. Forcing yourself to practice when you are not being productive and is not a good thing. Does more harm then good. I also always stop on a high note, meaning a good run out, cool shot, anything that I find positive.
I feel the use of all 15 balls in a drill can help with creativety in shot selection. The reason is that a shot is really two parts, pocketing the ball and getting the shape you want. With 15 balls on the table, this can be practiced all the time.
I use what I call 15 ball drill and the above is one version of it. Other version I use are:
Place all 15 balls between the foot corner pockets and the side pockets instead spread out all over the table.
One rail and back out. There are shots where just going into a rail and then back out you can get better shape for the next shot easier than trying to use stop or stun.
Use nothing but one type of english for all shots. Say, use inside to run all 15 balls.
Bank, Carom, Combo. That is the only type of shot you can make. No straight in shots allowed. You either hit a bank, carom or combo to run out the 15 balls.
By just rolling the balls out there on the table, there are times cluster happen, balls on the rail, things that are problems during a real game. If this happens, do not open the cluster or move the balls on the rail. Take this time to work on how to get rid of those problems. Learn the shot pattern that gets you into to shape for a ball on the rail shot.
The 15 ball drill and its variations is one of the strongest drills you can do. It covers everything.