Unlike the West, many happy ending or FS saunas have staff who know how to give an excellent massage. Go to any big sauna (the ones with lots of neon lighting) and ask the front desk for an expert.
On a side note to illustrate the environment in Asia :
I remember going to a big Macau sauna years ago for a legit massage. As I waited in the lounge, I enjoyed watching the lineups of girls in sexy lingerie/fishnet outfits who came to stand before the guys who opted for the FS service. Every time those lineups came out, the lounge manager would come out and ask me whether or not I would be interested in upgrading from the cheap legit massage from the on-site granny to the luxury FS + massage from a cute, nubile young-un.
I think the sauna deliberately made me wait quite awhile in the lounge before a granny was ready so they could saturate my eyeballs with all thos cuties doing the line-ups. Little did he know I only had enough cash for a legit one and I didn't want to put the luxury one on a credit card.