Posted without comment, but this came from a fellow tribologist from the sort of family that would be expected to have very good long case clocks as heirlooms.
"We inherited an old grandfather clock from my parents-in-law, which had been kept going by a local retired engineer who was a clock enthusiast. He offered to come and set it up after we had installed it where desired. Ah! I thought, now I shall see an expert at work. So he arrives, takes off the hood to expose the mechanism, checks the weights and their cables and then gets out the biggest can of WD40 I have ever seen and sprays the entire works for about ten seconds! And that was it. It is still going some ten years later, unlike the ancient engineer who has recently died.
I am looking at WD40 in a new light!"