Here's the GROSSEST Ice Bucket Challenge so far.  A woman in England wanted to do something unique, and asked her family to use a tanker truck on their farm to spray her down with water.

 

 

But instead, they pranked her by filling the tank with LIQUID MANURE.  (Search for "Stef Cowling - Ice Bucket Challenge with a Twist."  She gets sprayed at :18.)

 

 

(The way she sets it up, it sounds like she KNOWS it's going to be manure.  But she told the local news she thought it would be water.  WARNING:  She says the S-word at :16, the F-word at :47, and there's another S-word at 1:01.)