"Darky" is an old-fashioned term, now considered perjorative, for a black person.
"Dutch" in this case probably refers to a method of processing chocolate; recipes using chocolate are often called "double Dutch" to emphasize their chocolate deliciousness
"Double Dutch" is also a children's jumprope game; the rhythm of these lyrics is reminiscent of the rhythm of some of the chants used in jumprope. According to Wikipedia, Double Dutch "became an element of hip-hop culture," so it's possible that the term here refers to both the game and the chocolate.
"Kisses" may be a play on the usual kind and also a well-known chocolate candy produced by Hershey called "kisses."
"Back to Africa" may possibly refer to a historical movement in the 19th century US to send American blacks, both free and slave, back to Africa. Considering the rest of the song, probably not; but it's interesting to read about:
http://en.wikipedia.org/wiki/Back-to-Africa_movementI hope the vat at the wacky factory is self-explanatory.
ff beetje geinternet en je komt dit tegen....gaat een hele andere richting uit dan condooms met chocolade smaak