In the UK all Fuel has detergents and cleaners in it, I'm pretty certain this is true for the US as well. Why would you want to add even more?
If they are that bad you need to remove them and get them cleaned ultrasonically (or replaced). I know mine were spotless when last removed at 105k miles
Mad Mole
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Mad Moles Mondeo Madness 2L Zetec, Cams, Stage 2 head, Valve work, Powerflow, Unichip, AEM Ram, K&N, Ecotek, 75mm Lower etc.
192 BHP, Faster than a speeding Duratec!
