Well, I honestly have not found a way to really deter sphinx moths in the first place. Some of those give you the 2 nightshade-eating species of caterpillars. It's not that hornworms are not welcome here [they are cordially welcome!], but for many of these caterpillars and their eventual moths, tomato patches are a death-trap! My desire is to repel them so they will shine on folks like you and oviposit on natural host plants, which are also some of our most dreaded weeds.

Anyway, since you have them, hand-picking IS the best measure for hornworms. Bt is recommended, but I've heard it won't kill larger caterpillars. Beside that, live capture leaves the option for giving those big cats to neighbor kids, local elementary schools and maybe even a nature center. Sphinx moths are great, and far more beneficial than harmful.

Fruitworms are a different deal altogether. They are not splendid sphingids, but nasty noctuids. The moths don't feed, nor pollinate. They only collect at every porch and street light in town! In case you may not know, the same species is not only the fruitworm, but the gross, disgusting corn earworm [I HATE cornworms!] and the infamous cotton bollworm!