Hello! I have the exact same problem, although I do have some crusting and itching once in a while in the same place behind my right ear. What I do is when I shower in the morning, I take a pair of rough bath gloves, soap them up, and gently scrape away the dead skin.
When they are absorbed, they can be released in sweat through skin. Foods like yogurt, onions, garlic, red meat, cabbage, spices like coriander, and asparagus may result in increased body odor when consumed in large amounts. When you have a diet rich in proteins, you may have vinegar like smell on sweat.
Why sweat smells. Well actually sweat from the eccrine glands does not have a smell. Sweat from apocrine glands does have a smell, but it is usually only a very slight smell. However, our bodies have bacteria (germs) living on skin and clothes. These bacteria use sweat to grow. A lot of body smell (body odour or BO) comes from the bacteria feeding on the oils in sweat under the arms or groin.