I did it for a short period (< 4 weeks) and had no issues but also could not determine any additive/synergistic effects above and beyond what each does individually. I decided to use both separately first, then combined. I concluded I will use MK in PCT and GW prior to high-intensity training.
I retained some water on MK by itself (not abdominal "bloat") and never experienced the hunger issues. GW (in my opinion) is best used if you put in the effort (exercise). Combined, water retention was less but this was subjective and not adequately measured to come to a definitive answer.
Educate yourself on both (dosages, side effects, etc.) before proceeding.