It is quite hard to find genuine "Dongguan services" anymore, even in China. I was fortunate enough to visit Dongguan a few years before the Chinese government launched that massive, sweeping crackdown to wipe out its sex industry in one go, so I feel qualified to speak on this.
The defining characteristic of Dongguan's service was standardization—yes, you heard that right. While the services varied from one place to another, every single provider within the same shop delivered service that met or even exceeded a strict standard. After that crackdown, you couldn't find anywhere else in China that applied such a high degree of standardization to services. While individual SPs here and there might leave a strong impression with their attitude or specific techniques, no place ever offered Dongguan-style service again; it's truly a thing of the past.
If you really want to experience it, cities like Huizhou and Zhongshan in Guangdong province might still have a few traces left. Hong Kong is probably the most likely place you could still find something similar. But honestly, if you're looking for that kind of service, I'd strongly suggest going to Japan. After all, the tradition of Japanese Nuru massage hasn't been disrupted by crackdowns.
