fourty?

What does WD-40® stand for?
WD-40® literally stands for Water Displacement, 40th formula. That's the name straight out of the lab book used by the chemist who developed the product back in 1953. The chemist, Norm Larsen, was attempting to concoct a formula to prevent corrosion—a task which is done by displacing water. Norm's persistence paid off when he perfected the formula on his 40th try.
https://wd40.com/faqs

I have used wd40 on shuttle valves in offshore compressors to free off the shuttle valves .never had it wreck the seals .it just got blown out by the air. silicone grease or red rubber grease ( bit too thick) was used when rebuilding them. out on the job and no time to strip and clean it was wd40 or airtool oil that was used to free it off.