I stumbled into an optics development project over a decade ago. Today I develop multiple systems a year and know the math behind it pretty well, although I use the dedicated software. I’ve also worked on the manufacturing of lenses. I’ve always been into photography and hope to start a niche camera lens company in the US just like MS optics in Japan.
I use canola oil and salt and rub it in. Always cleans it out and the ingredients are cheap.