In the 1930s and 1940s, Julie Graves, a state health nurse, documented many of the early treatments and remedies used by midwives during pregnancy and childbirth. A document available online at the Florida State Archives' Florida Memory Project provides descriptions of many folk treatments, including this for ear problems:

For ear-ache fry a slightly bruised roach and put a drop or two of the resulting warm fluid or grease into the ear. Insert a small cloth or cotton to keep fluid in.

Unfortunately, the document doesn't explain the best method to "slightly bruise" a roach.