Quoted from AlexF:

I don't doubt the Dremel does a great job. With that said it does make a simple job more time consuming. I'll stick with the flex stone for now. It's never let me down in 14 years. Maybe someday when I have more time and I want that thoroughly detailed look.

Quoted from NicoVolta:

We all know Clay hates the Dremel. He prefers to sand things, and sometimes, sanding is the way to go. Like when high-current switch contacts become heavily pitted. But other times not... like using sandpaper to “clean” a bakelite full of rivets. Sure, it works, but it roughens up the rivet heads and flattens them out. Which isn’t ideal over the long-term.

Green pad scotchBrite works well for these. No rough edges. Just cut into squtes.

Using the alcohol swab/Dremel 443 polish/swab process is a gentle, time-consuming technique which provides the opportunity to:
Examine for loose/floating contacts (filing will not)
Does not introduce any grit or sandpaper dust
Does not change the strike angle of the contact via sanding/reshaping
Does work very well
Encourages full rebuilding of the relay versus “clean and go”
My technique is more oriented towards restorers and hobbyists, which are the vast majority of the EM world today. Clay’s perspective comes from that of an operator who needs to get old games running ASAP. Both methods work... it just depends upon which approach you need.
Personally, whenever I encounter a pitted switch contact (which is uncommon... most switches are smooth/convex even after years of wear) I use a Dremel flapwheel to sand them smooth and then polish with the 443.
However, the notion that using a Dremel to polish contacts is somehow “useless” and “makes things worse” and the “only” solution is to “grind away with a file” is... well... simply not true.
If switch pitting is a problem, doesn’t it make more sense to leave a smooth polished contact behind instead of a filed-down rough surface?
I could also argue that filing can change the switch gaps and deform the contact face, depending upon the technique used.
Ultimately, it’s all about the technique and the end result.
Some are Pinball Ninja, and some are Pinball Jedi... but whichever your path may the Force of the Gleaming Contacts be with you.