Used to brush gear oil on every 500km or so.
Bought a new bike this year that needed a new chain. Previous owner said he used chain lube "pretty regularly".
Yeah, I could tell. Years of caked, hardened lube everywhere. Embedded with dirt, grime, sand and other grit. Spent an hour scraping it all off, removing the chain guide, up around the front sprocket, etc.
I'm trying a new approach now. no "lube" per se, just cleaning with rag and oil once it gets dirty. Lube, especially the really sticky spray stuff, probably just promotes extra wear when it attracts road abrasives(?)