As good as it was I think Boeing has stopped using it due to what's in it.
I've no Boeing experience, but we use this stuff on our Airbus mainly in the fuel tank area, even better works PR1826B1-4 (if you need a B-sealant), but it's more expensive than the PR1422.
Both very unhealthy, but the best for your aircraft (like MEK and Mastinox
)