I have to ask: Play the same lick twice in the comfort in your practice room at home with no one listening. Record it and then listen to it a day later or so. Which one is better (one will be)?
Now do the same thing when someone you respect does SOMETHING in between and listen to them later. You will hear the SOMETHING being better whether you want to or not. Demos like this are 100% BS. That does not mean that Bob Malone does not know what he is doing, it means that you guys really didn't hear what you thought that you did. He may hear a relevant change, the audience will not!
The differences in clocking a mouthpiece or removing minimal amounts of dirt can change things BUT the player compensates for any changes the first times around. It could be hours, days, weeks before minor changes become second nature and not the product of compensation. The things that change during these BS demonstrations are never quantified if they are mentioned at all.
I have data on what exactly changes when we clean a receiver, set the gap, change the mass of the mouthpiece, change the back brace on the horn, change the mass of the receiver, drill out the throat. Admittedly, I have no data on clocking the mouthpiece, but in the light of the data that I do have, I feel that I can estimate the order of magnitude.
You heard what you were told to hear and that would not have survived a blind test for one simple reason: the playing consistency required for such a test is not humanly possible. A bit more or less vibrato, volume, dynamics would skew the results more than the change. When we get a placebo, we will play more confidently. In this case, the placebo COULD have long term benefits (at least long term power of suggestion, maybe more). That is not the point.
There is NOTHING wrong with clocking. For it to be technically significant we need to insure that many other aspects are covered. Live demos have a different purpose.