Nah the baking soda trick is legit but you gotta let it sit way longer than people say. I left mine on overnight once and the mug ring completely vanished, like it was never there. Also pro tip don't scrub too hard or you'll mess up the finish on the mug. Just gentle circular motions with a damp cloth after the paste dries. Saves you from buying those expensive stain removers that barely work anyway.
Yeah baking soda is a lifesaver. I once got red wine on my mom's white tablecloth and panicked, but a thick paste of that stuff sat for an hour and it was like it never happened. Still swear by it for like, any weird stain now.