Always used WD-40, What doesn't work very well is Ether starting fluid.
Quite a few years back, When I was younger and less intelligent, We were pulling some downed logs out of a small river, I got a little to close and deep with a 4 x4 ford pickup, and drowned out the motor.
No problem! Get out your old trusty can of WD out from the tool box; But all I had was a can of starting fluid.
Took off the distributor cap, and sprayed the hell out of it. Put the cap back on, and tried to start the truck.
All the kings horsemen couldn't have put that distributor cap back together again, Went off like Hiroshima.
My buddy kept as many pieces of the cap he could find, on his [trophy] shelf in the shop for several years. dave [acme thread]