automatic deletion of comments with certain words?

I use Akismet to guard again comment spam. It “errs” on the side of catching a few real comments, which suits me – except that if I don’t log on for a few days or so, I can have scores or hundreds of spam comments to wade through, checking for the occasional genuine one.

A lot of my spam comes from repeat offenders advertising the same things. Is there any way to get Akismet or some other thing to delete outright messages containing certain words?

Thanks