Actually M9, I am into cleaning. I've been exploding a *lot* of holds lately. I prefer to do that *before* I put myself in danger, because exploding holds have a fun habit of sometimes launching you backwards rather than downwards. Since I know it's your pet subject, yes, I'm 'primarily a boulderer'. I don't see much difference between cleaning the top of an 8m boulder problem and the first 8-10 metres of a route, particularly where you're going to be in a position you can't downclimb from. Grabbing moss at a high top-out is more than 'oh shit' moment, it's potentially death in some situations.
Cleaning a slabby grade 14 on which you can rest while you dig out shrubs is completely different to cleaning something vertical to overhung on which you might be resting on a hand jam in a dirty wet crack, at best. Or hanging off a free-standing 1 ton block.
So, this is getting weird, but Damo and I agree again.
Let's not confuse legitimate cleaning with an excuse for pre-inspection. One is done because you have a reasonable apprehension that you're going to get seriously hurt or killed; the other is because you think the route is too hard and wanted to 'just go brush off that hold a bit' (yeah right).
Speaking of cleaning, anyone used oxygen bleach to destroy (massive quantities of) moss? Apparently it biodegrades as salt.