I think the cannibalism interpretation is funnier, because it’s so unlikely.
Perfect combination of post and poster. 
‘It’s going to have to be Manhattan style. She’s on her period.’
Sorry for being so obtuse, but I don’t know what this means.
I don’t get the water taxi thing either.
Oh, and “sexual”.
“I only like all-natural foods and beverages, organically grown, with no preservatives. Are you sure they’re real lemons?”
QED
Oh, and sexual, but I first heard that joke when I was maybe in 7th grade.
Read it here for the first time…thought it was drug related.
but Dutch scouts use junglebook names
I actually assumed that the point was that the less sexually enlightened would think it had to do with cannibalism, so that the others had the defense of claiming it wasn’t a dirty joke. Your mind just made it dirty.
The version I heard was:
Q: What’s white and comes in brownies?
A: Roman Polanski.
The version I learned was totally non-ambiguous:
“Why do men like to eat Brownies?”
“Because with Girl Scouts, you get hairs caught in your teeth.”
Which not only clearly disambiguates the sexual connotations, but emphasizes the pedophiliac nature of the described situation. Yeah, I went to school with some real cards, let me tell you.