Had a good look through Nathan's 'Dan Emmett and the rise of Negro Minstrelsy'. As I suspected might be the case nothing written by Emmett is relevant here except obviously some of his more famous songs were sung at sea and possibly even used as capstan chanties, Dixie for instance.

However an example of a corn-shucking song from S. carolina is given as possibly influencing some minstrel songs, and it certainly can be related to 2 different chanties.

Johnny come down de hollow. Oh hollow!
Johnny come down de hollow. Oh hollow!
De nigger-trader got me. Oh Hollow!
De speculater bought me. Oh hollow!
I'm sold for silver dollars. Oh hollow!
Boys, go catch de pony. Oh hollow!
Bring him round de corner. Oh hollow!
I'm goin' away to Georgia. Oh hollow!
Boys, good-bye for ever. Oh hollow!

Might help to clear up where 'Hilo' came from, and the other connection is obvious, Shallo Brown.

Off to have a look through Courlander now.