Is it ok to clean your navel with saline water and put antibiotic ointment on it 5 days after a tummy tuck?

Thank you so much for share with us your concern. It's ok to clean your belly bottoms with saline and antibiotic ointment at 5 days after surgery. However, you should contact your Board Certified Plastic Surgeon for any doubt that you have after surgery, he should have given you instructions after surgery that should strictly follow. 
Best of luck!
Dr. Quiroz 

It is best for you to follow up with your surgeon for post operative instructions.  He/She is most familiar with the details of your surgery and how you've been progressing through recovery.

Thank you for your question! It is very important to follow the instructions given by your plastic surgeon. I recommend discussing care of incisions with him/her. Best of luck!