Just pull all the hair out, flush it down the loo and give it a rinse under the tap. It'll be fine!
It was on HUKD earlier about a £1 shop version that's almost the same, worth checking out if you're after one. I, personally, thought it was crap, and a waste of £13. Didn't go througn DD's super thick hair. Not too bad on mine now, but as I've got a pixie crop, that's not hard.