Let us not debate here!
I have had 32 years of practical experience coating using hand blades, x-hopper, slide and curtain. I know what I'm doing. I have used anionic, cationic and nonionic surfactants. My results are proven and I have samples to show the students who take the course. I have demostrated this for fellow engineers here at my home and elsewhere. It works. I have the patents and internal reports to prove it!
I'm sorry it doesn't make you happy that I am getting results that seem to you to be at odds with yours. Now, lets drop the matter.
As for the price, I don't set that. The sponsoring institution does!
Go talk to them! Set up your own workshops. Whatever. But please don't belittle my efforts, results or my knowledge. Don't comment on the cost. I have nothing more to do with that than you would in my position.
I'm sure that your work is just fine and that you are doing well. Good luck to you.