Actually,this is not the case.
What it does is allow the fuel to be operated at a higher temp within the engine fuel system before the fuel breaks down into coke deposits and laquers. So it can help keep the fuel system cleaner and also reduces afterburner problems. RR have not approved it yet but it is undergoing evaluation. Hear it is currently being trialed in a few Goshawks in the US. It is already fully approved by GE and PW.