Hi,
You probably should not be digging into your belly button with a q-tip, that is asking for irritation.
Clean it gently with soap and water and pat dry. Some people may use a little rubbing alcohol to dry it as well.
It is quite normal for some odor from belly button. But if dry and no discharge you should probably leave it alone.
If there is an infection, or a discharge, you may need a topical antibiotic cream from your Dr.