The main problem with wd40 or any solvent put in a Leica is how easily it can get to both the shutter and the rangefinder. Everything is mechanically connected inside that body and those are two places you don't want any oil or solvent. But using a little on a brush to clean won't do any harm.
What set off the alarm bells and caused the uproar and indignation was:
Also, people just generally need to poo-poo. But everything @Light Capture said above is true - that's the guy who repaired my Hasselblad. There's a difference between the people who only say what you shouldn't do and those who say what you should. The former are generally not worth paying attention to.
What set off the alarm bells and caused the uproar and indignation was:
which sounds like "let wd40 or naphtha run freely into the camera.run some WD-40 or naphtha into the mechanism
Also, people just generally need to poo-poo. But everything @Light Capture said above is true - that's the guy who repaired my Hasselblad. There's a difference between the people who only say what you shouldn't do and those who say what you should. The former are generally not worth paying attention to.