The best move is to search directly by specific dance names: try hashtags like #jota, #sevillanas, #tarantula or #fandango and filter by longer videos (the short ones tend to be made-up choreography more than anything else). It'll also help you search by regions, like #danzasextremenas or #danzasdellevante, because a lot of creators organize their content that way and they tend to be more rigorous.
What works pretty well is following actual folk groups or professional dancers who have TikTok accounts. Not all of them are on there, but the ones who are usually share snippets of their teachings or rehearsals, and you can really tell the difference in quality and authenticity. Also look for creators who mention being linked to traditional dance academies or cultural associations; those videos are on another level even if they're short.
One more trick: check platforms like YouTube where there are channels specialized in folk dances (way more extensive than TikTok) and then see if those same creators have TikTok. TikTok's algorithm is pretty good, so once you find a couple of real creators, it'll start suggesting similar content to you. Be patient with the first few days of searching, but after that your feed fills up with what you need 😊