I've a ceramic hob.I use Cif and a scourer then my metal fish slice (of all things!!) on the really stubborn bits ,very gently. You can also use one of those window scraper things with a blade in. The top is just glass so it's just like getting dried paint off a window. I've just done my friend's halogen hob the same way (I'm house sitting for her) Looks like new. I've tried Hob Brite and it's rubbish. Whatever you use just do it gently and it'll be fine.