Here’s what I do:
1. After emptying the fridge & freezer following a trip, dry the interior of both compartments completely.
2. Wipe/clean all the surfaces: walls, shelves, and door shelves with either vinegar water or baking soda water after every trip. Allow to dry before closing fridge/freezer doors.
3. Store with either Bamboo Charcoal Air Purifying bags or leaving the doors clipped open as FlyBob described above.
4. When preparing for the next trip, check fridge for any spots that need cleaning and check for unpleasant odors. If either is detected, repeat Step 2, above.
Then we’re ready to go!
We’ve never had smells while fridge is in use, and I don’t use baking soda or fans inside (except as noted).