Engaging in sexual activities with a Clown, with clock referring to a Clown's cock and "clicking" corresponding to whatever sexual act you have in mind. ;)
Zach: "Hey Nathan, have you seen Julia around anywhere today?"
Nathan: "I am pretty sure that she went to the State Fair to click on that clock!"
or
The adults of Derry, Maine ventured into the sewers to click on that clock.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.