I'll see if I can lend a hand. IMO Zaino seems to be a mild lsp, so the hd cleanse should be able to remove it (provided that there isn't a lot of it caked on from years of accumulation). What I would do is to (by hand) clay, then use a paint cleaner that's hand friendly (megs, mother's, gliptone for otc; Sonus may also work, but their polishes are more geared toward rotary and pc buffers).
Follow the paint cleaner with the HD Cleanse, and then you can apply Concours as directed by Zymol. I have been hearing how some people like using a QD or Field Glaze right after the application of a Zymol; I personally would not recommend using a qd on a freshly applied EGZymol. A fresh coat of an EGZymol, to my eye, has the most potent look and the most violent color response when its applied new, and all by itself without the aid of a qd. After a coat of zymol is applied, I would come back to finish with a final wipe-down with either atomized water and a well graded mf, or if you prefer, it can be done dry provided that there isn't any lingering dust on the surface.
After the zymol has gotten at least a couple of weeks old, then IMO you can apply a very mild QD to cut some lingering haze and provide a hint of moistness. I'm not really a fan of the Field Glaze (sounds funny), as it has left my surface on a couple occasions with a greasy look. Some may call that look "wet", but it didn't look particularly clear when I used it, as opposed to one or two good qd's I've used since trying out Field Glaze. Experiment with one or two brands as well as Field Glaze, and see which one will support your zymol finish the best.
Good luck.
Edit: Any reputable name shampoo should help maintain your finish, provided that it is wax friendly (supposedly non-wax stripping). I have used Mother's CG shampoo for many years, and so far it has provided the best cleaning effect while maintaining my wax finishes. Black Magic shampoo is also a good choice.
