Another suggestion if above not sufficient:
You could try cleaning with washing soda crystals, ( it used to be big crystals, today it is more like powder !). Not sure it is still called crystals actually - might just be 'washing soda'.
Dilute several heaped tablespoons full in a small bowl very very hot water. Whilst water still very hot, wash out and also scrub into corners of freezer section and any other bits that have little crannies with washing up brush or even a tooth brush (if you have an old one she swiftly adds).
Leave it unrinsed for a while before washing out and wiping clean. Repeat process twice if not smelling sweeter. Try removing the door and cleaning that - I suspect it is all in the crevices at the sides and back.
I always leave fridge door open and ice tray wedged in the freezer door opening to keep it all open when not in use. Even if just a week.