>I'd prefer councils to fund public toilets properly, but in the absence of that I suppose this is the next best thing.
Agreed.

One of the four bars listed on that site (Cubana) is a place I've been to twice and from both experiences, it's a stupid choice for evening piddlers. It's one of the busiest bars in the area and the scheme will not work properly there. You're lucky if you get a chance to piss in there as a customer. Though I'm not sure if it's open during the daytime, in which case it would probably be a lot more free. And to be perfectly honest, I can't say I've noticed any clear and visible sign announcing its public utility.