I think they work.
In the UK, attack ads (and really, ads in general) are almost exclusively Conservative, from what I've seen. Some are absolutely disastrous, like the paralysed David Cameron staring at a camera. Actually, the attack ads are the best; for example, the ones with Gordon Brown doing his disturbing smile with the sarcastic statements (e.g. "I tripled the deficit, let me do it again"). There is nothing wrong with attacking the other parties, especially in a country where everyone hates all of the parties for one reason or another anyway.
They don't help me vote personally, because:
i) Election ads in general are completely different to government policy
ii) I'm never going to vote anything other than Tory anyway.
But they help people to vote, certainly.
(Former) Lead Moderator and (Eternal) VGC Detective 
