It's a nice idea in theory - in practice, I just don't see how it will work - most people you approach in an airport will back off / assume there is a catch / not want to be disturbed, so your generous gesture will probably get (wrongly) a bad reaction; and from your point of view, you don't know this person - what if they don't behave in the CCR, get drunk, start a fight, pester you? None of that is VERY likely, but you just don't know if you pick a random person!

I can just about see how if I had struck up a conversation in a queue or something and it felt natural I might offer to guest someone (maybe...it's not happened yet...) but I can't see this working otherwise.

For a start, you'd have to be very selective about who to ask...I would (for example) not approach any solo female passengers with this sort of idea as it could very easily be taken the wrong way even if not intended!

Honestly, it's a nice idea but I wouldn't recommend it. If by chance you strike up a conversation with someone and it flows from there, sure; otherwise, just go enjoy the CCR by yourself, your enjoyment won't be any the less for having not "used" your full "entitlement" (by the same token, I don't arrive at the airport 4 hours early just to extend my stay in the lounge - I use it as intended which is for my own convenience; if what is convenient is a mere 20 minute pit stop in the CCR for a quick coffee or drink, that's just fine - the greatest luxury is the flexibility!)