Thanks for posting this... just bought a SS that has this exact issue and the seller did not note this problem to me. Was going to get rid of this one and buy another, in correct operating condition. You saved me from making another mistake! Excellent!!!
I've read the label on that & it's full of safety warnings that suggest it is somewhat corrosive (which Is why I chose to buy a different product) so I am inclined to advise against using it on metal.
I think Kaboom! is just rebranded Scrubbing Bubbles with oxyclean added. A couple months before Kaboom! came out, the Scrubbing Bubbles with the blue foam indicator disappeared from store shelves.
I would not use Kaboom. Different company than Scrubbing Bubbles and it has bleach. It's used in bathrooms for mold and mildew.
Interesting thread. About 2 years ago I bought a 1936 Gillette Aristocrat in an antique store for $8. It was a good attractive razor except it had the dropped knob problem. I closed the razor's doors and pushed the dropped knob up to the normal position, wrapped a thick towel around the handle , and crimped the handle with a pair of vice grip pliers slightly above where the handle would drop. I rotated the handle and squeezed hard in different positions maybe 4 or 5 times. It was fixed. No scratches. Nothing bent. Doors open and close completely and smoothly. Maybe I was lucky but my simplified method worked.