In reply to Johnlenham:
It’s pretty easy really just climb the starred routes if its a big concern of yours, or look for a crag with the biggest concentration of them.
When you get into outdoor climbing It generally becomes less of a concern as you start to appreciate the nature of climbing on, well, nature.
By clean (Wye, cheddar) sounds like you want to climb somewhere polished!
As much as I think you should just get out there and climb and not be fussy, I would recommend places like Tirpentws, Navigation, Gilwern, Sirhowy, Rhossili etc.
Any route with a star or more, and most routes under 6b+ will likely be well travelled and clean (and polished if they also have a bunch of stars)
edit: potentially you’re just asking out of curiosity and not necessarily preference which is fair enough!
Post edited at 23:50