Why are so many empty Vaseline containers appearing on this road in Calgary?

No one can explain why empty jars of Vaseline keep showing up on 68th Street N.E. in northeast Calgary. It's been going on for at least five years. There's even one of them in Google Street View, as you can see in this photo:

Rodel Bique, who works for the city of Calgary on the road crew, told CBC: "Too much. Too much Vaseline bottles here. We cannot count it. Maybe an average of 15 bottles, 15 to 20 in a month."

Unanswered questions: Who is using the Vaseline? For what purpose? And why are they throwing the empty containers in the street?

By the way, there are a lot of songs about Vaseline. The one by Elastica is the best, FYI: