Why does my dog roll in fox poo? and how do i get rid of the smell?

my 10 month old lab wont stop rolling in fox poo the problem is he's to big for me to bath so i struggle in the garden with soap and a bucket of water its a huge inconvenience its stressful and no matter how much shampoo and doggie deodorant i use i cant get rid of the smell how do i stop him doing this and get rid of this awful smell.