I don't think making ricotta cheese, and then taking the leftover whey and working with it is an alchemical secret by any means - it is an interesting experiment, and I think has the potential to be "alchemical" depending on the operator. I went through most of the steps of that process that Kibric posted to see what was going on - it did not resonate with me. Still though - learned to make ricotta, and started thinking differently about milk in general.
There are secrets men keep or try to force others to keep for various reasons, often not pure. I've had people "reveal" to me deep secrets in private messages which I did not ask for, trying to bind me to to promise never to reveal them, even though you can find this same information in a simple google search. These types of people have an agenda - best to stay away from them. At the same time, you will find most people will reveal to your their deepest secrets without knowing. It oozes out, and their attempt at not saying something they wish to hide often ends up being expressed in the spaces between their words. Read up on King Midas and the reeds of Pan!
The only "secrets" that are naturally kept, I think, occur because of the nature of knowledge / language / consciousness. The secret wraps itself in these things to express itself, and simultaneously hides its true nature, with that expressing being an outer cloak or shell. It's more correct in my mind to say that our attempts at understanding the nature of this "secret" naturally creates a lie, because we can only imperfectly represent it. That label we give, "secret" is itself not entirely correct either.
The spirit seeks expression in matter, and interacts with matter, and takes on the forms of matter, and as it does this it envelops itself with two other things - a soul and a body. Neither the soul nor the body are a correct representation of the spirit, but what can be said of the spirit as it is, devoid of its soul and body? All the things that are said of it are contradictory, fantastical, and not at all aligned with the understanding of how things work from the point of view of a language that has developed in relation to explaining the phenomena of the soul and the body. You can't really "reveal" this either - I mean you can try, to the best of your ability, but many others will not even notice you did so. You can shout it from the rooftops and no one hears.
On the nature of mental illnesses in general much can be said. It takes a wide variety of forms. There's been people on this forum that have had mental breaks due to drugs / alcohol usage, and even by being led on by the hallucinations of the AI chatbots they interact with.
So much of what is common knowledge nowadays, especially surrounding certain materials, was historically kept as a secret. Many times, most times actually, it was protectionism measures to ensure "competition" could not also have it. That's the problem - that mentality, which brings up that word "competition". It's that old dog once again, the Ego, seeking to limit, and to control.
Now, if you are involved in a conversation or interaction with yourself, a higher self, or some construct or understanding that involves these things, and there are secrets involved, which, for whatever reason, have bound you to limitations of what you can and cannot reveal, then by all means, follow that path, otherwise you get to face the consequences of not following that path. Like so many other things, we create these realities ourselves.