Help! How to get my tummy tuck incision to heal faster? (Photo)

It appears your plastic surgeon keeping the area clean and moist with saline is doing an excellent job of wound healing.  Also, the antibiotics you are on should decrease the chance of bacterial contamination of these open areas until they can heal.  That being said, if you were my patient, I would add in a topical antibiotic to again decrease the bacterial count specifically at the point where you want the wound healing.  Very often, packing these small wounds with Iodoform gauze will also speed wound healing.  The gauze itself allows tissue to heal at the base first, then close the wound. 

Occaisionally small areas may open after surgery. Usually they are very minor and will heal quickly with proper care. There are many different ways to encourage healing so you should follow your surgeon's advice. In general though you want to keep the area clean, and apply an occlussive dressing which keeps your body's healing factors inside where they need to work. Do not let it stay open to the air where it will dry out and take longer for it to heal. good luck.

It certainly seems as though your plastic surgeon is taking very good care of you. I would suggest that you continue to follow your surgeon's advice.  Saline wet to dry dressing changes are a time proven effective dressing.