The quote is originally from the movie Grown Ups, where Adam Sandler's character answers a table of kids wanting to know what being "wasted" means and he tells them it's a "hankering for ice cream". A little girl then yells out "I wanna get chocolate wasted!".
People now use it just to mean very drunk and they generally use the complete quote from the movie.
Sam: Yeah, I could use a few drinks after all this studying.
Kara: I wanna get chocolate wasted!!
Everyone: (laughs hysterically)
liam: uhhh what?
me: you know??? when you eat a shitload of chocolate and you are wasted off it!!