What would be the best chemical or product to apply to asphalt singles
(architectural 25-year)?

I know you're supposed to put a little bleach in with the mix but what should I
ask for? Just a generic mold/mildew remover or is there something specific for
use on asphalt shingles?

Also, any "home remedies" would be welcome if you know of any better methods.

For the record, this roof is in FL and is not BAD. It just shows some darkening
in some areas which has been typical of being mold / mildew on the roof which
happens after a few years here.