"Remove Formatting" from ALL posts at once

I’ve just imported a ton of posts from an old website. I need to “Remove Formatting” from all posts but I’d rather not have to go into each one individually and hit the “Remove Formatting” button.

Is there a script I could run to “Remove Formatting” from all posts at once? I can’t find a plugin for it…. :-/

Any pointers in the right direction would be much appreciated.