That is some precision, very interesting method. I'm assuming this has worked well for you?
It kind of does now. I heeded to the youtube videos on knocking in and went ballistic for the first couple of bats - An SG Sunny Tonny and a Slazenger V12. Suffice to say that I ended up knocking them so deep that the bat ended up being as hard as the mallet, destroying the ping and the pressing done by the manufacturer for optimum performance. Had to retire these bats to tennis ball cricket, thanks to being unplayable.
In reality, it is better to have a bat that is knocked slightly lesser (other than edges and toe that is) than knocking it excessively thereby turning the bat into an unplayable proposition. There is no going back once it is excessively knocked. Learnt my lesson and started to respect the pressing done by bat makers a bit. Simple lesson, don't go ballistic. For most modern bats, 2 to 3 hours of work with the mallet is more than enough, with one hour going for edges and toe. As mentioned, the bat will lose a bit of performance immediately after knocking. But then, it is a hardened face of the bat with a stiff handle against a ball. The bat is much safer and will last longer. Once the handle loosens up during the nets, it will play fantastic.