So, quick summary of my findings:
1) Freelancers: I tried SA, but girls were asking for crazy money (2-3x what I hear it would be in Blighty) - I am a total noob at SA, so this could be down to my poor understanding of the concept and how to negotiate. Anyway, was not for me.
2) Spas: I went to SkyRiver. Was not for me - hot girls, but total conveyor belt routine. I was in/out in 30 mins. Price was RM238 full service. A bit higher price for Chinese girls.
3) Massage parlours: This worked fantastically well for me. But I mixed it with WeChat.
You basically go to any busy area (typically close to one of the many many malls there) and open WeChat. There you will find the nearby massage places advertise their services. Generally they will not give you all details through WeChat, but if you ask for a 'naughty' massage, and if they say 'yes' - then you can be sure they are open to what ever you desire. It did not fail for me. One hint though, do not go for the malls in the center-ish of KL. Go to the malls in the surrounding areas where the local people hang out. I had several fantastic massages+fj+BJ/CIM/etc from super hot and cute Malay girls with this technique.
Typically you pay RM60 for the massage, and negotiate from 50-100 extra for the services on top. All the girls I met this way were part timers with other jobs. They were happy to share their private contact info (whatsapp/wechat) and to meet again at my hotel. I was too busy to ever take anyone up on the offer - but if I went again, this could be a plan-b.
Finally - Last two nights I tried Tinder and there were so many pro's on there. Pricing was around RM4-500/night for what looked like super hot girls. What was even better though, was the abundance of hot girls that was just looking for NSA fun.
Like SA, I had never actually tried Tinder. I was just honest, putting something like: 'here for another 2 days, looking for a good time - want to join me?' wording on my profile. And I invested in Tinder Gold so I got transparency into the likes. Got +50 inbound contacts the first night that way. I had the best experiences of my trip with a young girl from Tinder - no money exchanged.
KL is a pretty cool place!