Raccoons do their business - Latest

Its been a while. Rob and Roy the noisy raccoons, visit at regular intervals, and I hesitate to mention it, but I must, they have made the base of our cedar tree their latrine. "Up with this I will not put", to quote Winston Churchill, so we're trying to work out a mechanism of deterring the beasts from visiting in such a manner. Various sticks and staves have been tried to no avail. So if you know how to discourage raccoons (without shooting them), then please meander down to the comments section and leave your advice. It would be so much appreciated.