Getting rid of Open With duplicates – All this:
You right-click its icon in the Finder, choose Open With, and a submenu pops up with an absurd number of duplicate entries.
When you first noticed the duplicates, it was just one or two and you didn’t want to take the time to find out how to fix it, but now you’re kind of pissed at your Mac for being so stupid.
It’s so annoying having a lot of duplicates, or all Windows apps in the “Open With…” sub-menu when right clicking. This article solved it nicely! Saved here for my own reference.