I've been to Dōgo Onsen several times, but I had no idea of the putative connection to Spirited Away. If you'd asked me at the time, I never would have made the connection based on visuals alone. They're really overstating the case.

Point being: please don't rush here based on this article. It's an old bathhouse with tiny baths and a somewhat unique interior for Japan. The most interesting part is honestly the imperial bath suite, which is a museum that can only be accessed via appointment. The "Spirited Away bathhouse" is an entirely fictional construct based on a bunch of different locations, and Ghibli has said that there's no existing bathhouse that models the one on the movie.

I hate this kind of lazy tourist porn. For the past several years everyone has been overcrowding Shima Onsen in Gunma, because the outside of that one looks a bit like the movie, and lots of articles were written saying the same things. If you want Ghibli, go to the museum in Tokyo, and don't overwhelm random places looking for something that doesn't exist.