Odor relates to bacteria residing in warm, wet, dead tissue. Better cleansing will eliminate this. To accomplish better wound care, you should perform more dressing changes per day, let the dried "stuff" stick to the gauze as you pull it away (in other words, do not moisten the dressing so it comes out easily), and feel free to gently scrub the wound with a soft-bristle toothbrush! This accomplishes what your surgeon did when he "cleaned the wound with instruments." Remember, if light bleeding occurs, healthy tissues bleed, whereas dead tissue does not, so don't let a little red ooze scare you!
Your instruments are a bit less metallic and sharp, but you can (and should) accomplish the same goal with daily wound toothbrush scrubs in the shower, more frequent wet-dry dressing changes, and follow-up with your surgeon as recommended. Please verify that your surgeon is in agreement with any recommendation from someone who has not seen your wound in person (all of us), but rest assured that this will continue to heal and leave a remarkably smaller scar than you now suspect.
BTW, hydrogen peroxide is sometimes recommended for an infected or contaminated wound. It is OK for once or twice, but chronic use can actually slow healing, so stick with soap, water, scrubbing, and bandage changes per your surgeon's advice. Good luck!