.." WD40 is bad for guns " Really ? no evidence of that as I've used it for the past 40-50 yrs.
I posted that I use it as a solvent/cleaner, not as a lube, or for long term storage.
It's a great solvent, for removing carbon fouling, old built up, hardened oil, grease, etc.. been using it from close to 50 yrs..
After spraying, then letting it soak for awhile, I wipe it off, use q-tips, rags, paper towels, etc ..to clean off residue that hasn't washed off.
After cleaning metal surfaces, I go over surfaces with an oil, Hoppes #9, or the past few yrs... FP-10
I've never had it harm a finish, either..don't intentionally spray it on wood, but I do wipe it off when any gets on it.