IF this is the case than you can go for optical phase conjugation along with FBG and DCF to suppress FWM.Because i have seen work on hybrid modulators and modulation formats.Also on OPC ,but you may try different combinations for the control of FWM in system.
Here i have given a link for article from optik
http://www.researchgate.net/publication/261716528_Suppression_of_four_wave_mixing_in_wavelength_division_multiplexed_system_with_hybrid_modules
Kindly study it and let me know if it helps