Has anyone used Bulb Grease on spark plug wires? I can see no reason why it wouldn't work. It is waterproof and conductive.

"Bulb grease" means whatever the marketer wants it to mean; there's no standard, but conductive is the opposite of what you want on spark plug and coil boots! The grease you use in those places is dielectric (very much does not conduct electricity).

Sil-Glyde or tune-up grease or "dielectric grease" is what to use.

There is plenty of conduction between the metal plug wire terminal and the metal spark plug terminal—if not, then the fix is to replace the faulty plug wire or plug. No assist is needed from grease or any other compound. The point of using grease is to prevent the plug wire boots sticking to the plugs, coil tower, and distributor cap terminals—as well as to provide an extra barrier to prevent electricity leaking to ground between the boot and the spark plug insulator, causing a carbon track and permanent short to ground.

But the grease has to be dielectric—nonconductive. Put conductive gunk on, and you're practically guaranteeing yourself a great deal of misfiring (at best), as you're handing, on a silver platter, the ignition secondary current a beautifully landscaped, nicely paved path to ground.

it also helps prevent corrosion as well.

Just to share...too much slick can also cause an issue with plugs boots. I recall something GM from the 90s that dielectric silicone would allow the plug boots to slide off on their own. It might have been on a coil pack connection, my memory gets fuzzy on the off brands after awhile.

That is certainly its purpose in its nominal application—to prevent corrosion at the bulb/socket junction. Here again, only a thin film is necessary, not big globs. And it's best to use bulbs with nickel-plated bases rather than plain brass; that way the grease is pretty much entirely unneeded and bulb-corroded-into-socket stops being possible.

(if there's any water inside the boots on either end of any of the spark plug wires, presence or absence of grease is the least of our worries)