Do the individual ingredients in the Cleggs cocktail have a shelf life?

They do have a shelf life, not sure how long, but I usually use up Weed Free Zone and Atrazine in a year or 2.

You adding surfactant to the mixture?

Anyway you are using a good product in MSM Turf just be sure you are adding surfactant, particularly important with dollarweed with those waxy leaves.

Dollarweed and VBW are warm season perennials - perennials are almost always more difficult to control - and invariability require multiple sprays. Follow up with additional sprays at 3 or 4 week intervals if warranted. Be persistent, but patient, and you’ll eventually get on top of them.