That’s handy to know, also in the NW of England. I am now using sea drops and have had good success. Been on now for a few weeks, and has been fine. There is a spot of dirt on the lens ATM, so it needs wiping anyway. When I do, I’ll apply a little more. Read somewhere recently that spit is really good too, lol. If it works, it works and is quick and cheap.
Interestingly, I only get it on one camera. I have three at home, and four at a remote location, much damper than here, right next to a river, and none of the others do it. It’s only the one that faces almost due north, and is lower down, nearer the ground. Definitely not the camera itself, because I have switched two around, to check.
Anyway, looks like anything that behaves as a surfactant will do the trick.