it ain't dry, but it works
I use this method because Twitter populates a lot of stuff via Ajax. I experimented with inlining LiveQuery into default.js, but it was too much of a PITA
Why don't you just remove them?
$('.trends-inner, p.promo, .user-rec-component, .component-spacer').remove()
removing doesn't work because they're dynamically added after the page load. dotjs fires at load time.
Makes sense. Lamesauce.