I'd recommend you use Poorboys Bold n Bright. It's water based (if you're worried about fuking up your o2 sensors), not greasy and dust/dirt doesn't stick to it. Wipe it on (i use a tyre foam thing, the C shaped ones).
It doubles as it 'cleans' as well (id still clean it a bit first with degreaser and brush) as gives it that matte black new look.
On top of this, it lasts much longer than anything else i've tried.
I think $20 a bottle from waxit