Back in the late 80’s a high end audio shop in Phoenix recommended Armorall on our CD’s.I have read that you shouldn’t use Armor All. That it has some longterm detrimental effect. I never tried it myself.
I believe that the rationale for disc treatment is that the polycarbonate surface is rough, microscopically speaking, and treatments give you a smoother surface causing less scattering/better focusing of the laser.
Did I just agree with Geoff???