To what extent should Cameron and Clegg use Brown’s gaffe against him?

Given the timing of Brown’s Mega Gaffe, you’ve got to wonder how it will play out in the TV debate tonight.  Will it, for instance, mean that he gets a hostile reception?  Will he try to defuse the situation by repeating his apologies, or perhaps by making some sort of light out of it (“Yesterday, I met a woman in Rochdale…”)?  Will it overwhelm the deeply serious economic questions which need asking and answering?  And so on.

There’s one question, in particular, though, that I’d be keen to hear CoffeeHousers’ views on: how much should Cameron and Clegg use Brown’s gaffe against him?  My thinking is that they’ve played it well so far – only offering limited comment along the lines of “I think the words speak for themselves” – and that they should continue the same approach tonight.  If they say anything more direct, if they politicise the situation ahead of talking about the economy, then they risk triggering the (slight) possibility of a sympathy backlash in the PM’s favour.