OKC worked for me but it took a really long time (2+ years, on and off). Didn't really get into Tinder and didn't try the others.
Edit: wait am I the Glaswegian you were talking about? I can't keep track of what I post anymore.
You were indeed!
I still have a good story of a woman on OKC saying she was busy for an entire month, and it wasn't a holiday/trip. It brings a smile to my face.