Have to say I'm actually pulling back from being overly clinical on the dialog cleanup - it all passes QC etc but after listening back to one show I thought it lacked life or a bit of naturalness because I'd totally overdone it.

As for cutting it out at the recording stage, I've tried most things and some artists really are just 'noisy'.  As mentioned above, the good ones know their voice and know retakes are a part of the process.  Kids dialog on the other hand are just hard work full-stop ;-)