Quit smoking and spend more money on your car.
ITs take a while. One I did to my supplier in Jap took 4 days to clear, it was a shit tin of cash too, about 20' worth.
Id replace both. If you do try to buy a set of nismo ones, they are more expensive but have the same characteristics of a Z32 meter which is good if you make some more serious mods to the motor.
Willal Engineering have done a lot of work on E85 and tuning packages. They also have their own range of fluids that are R35 specific. Mercury Motorsports here in Brisbane have done a big job on a local car which has just been made a track only vehicle.