I flush with WD40, spin a bit and flush again. I flush from the outside face of the freewheel to the inside face. I flush and spin until I see WD40 leaking out of the inner face. Then I blow (don't have a compressor) in an effort to push as much of the contaminated WD40 out (again, working from the outside face to the inner face. Repeat a few times then I liberally flush the freewheel with ProLink and, finally, some light oil, again flushing until you are sure that the oil has begun to seep through. That's all there is to it and been doing it for many years.