Have you tried learning a language by immersion only? How did you do it? Would you recommend it?

As a native Italian speaker, a few years ago I think I learned both Spanish and Portuguese mainly by immersion. What I mean by immersion is that for both languages I first began watching series (some easy binge watching), reading magazines and books (the most useful in my opinion to acquire vocabulary). Then at some point I visited the respective countries and started to attempt speaking. I can share more details, however in both cases I had to work with native speakers who didn't speak English, so I was really forced to use the language. I kinda had the ideal setting for learning by immersion!

In the long term, I eventually realised I missed some advanced grammar and had a look at them, but kind of afterwards, after achieving a solid confidence in using the language.

That said, I think I believe that was possible for the proximity of the languages but I couldn't image doing the same for other languages such as Japanese or Korean for instance.

So I am wondering if anyone actually tried learning a language by immersion? Maybe a language not so close to their native one?