Just want to keep my boots from ripping and to keep them lasting.

 

Spray? Not that ive heard. Just dont abuse your car and you shouldnt have problems. Ie: Getting into the gas hard with the wheels turned, dumping the clutch at 6000 rpm's.
Just take care not to over run your car as it sits at the time.

 

Some people use silcone spray on the boots. Axles are so cheap anymore I don't even bother.

 

ummm some stuff called aerospace protectant...its a rub on thing...should be able to get it at autozone or something like that