Dog Borstal

This entry in the BBC programme listings caught my eye:

"Some of the worst dogs in Britain come face to face with three trainers...".

I suppose by "worst" the BBC means "naughtiest"?

I have to say a few questions spring to mind:

• How were the dogs selected? Did they have to go through regional heats, with perhaps Graham Norton or Rolf Harris on hand to console the luckless losers?
• What exactly were the criteria for naughtiness? Naughtiness, I have always found, is very much in the eye of the beholder.

Finally, I note that the trainers' brief is, in the words of no less an authority than the BBC itself, to "cut them [the dogs] down to size". Surely that should read "lick them into shape"?