To return, briefly, to "Suss":-

Halliwell* gives two obsolete entries for "Suss" - The first was a slang term, from the Isle of Wight, for a dog-fish; nd the second was an Eastern (he gves no narrower area than that) term for to "swill like a hog" (with the example "a call to a swine to eat their suss or hog-wash."

For my own part, I seem to recall 'suss' (or 'sussing out') being used (in the very late sixties/v. early seveties) as a term for cunnilingus - but this IIRC was fairly short lived.

W


*Dictionary of Archaic Words