Ass preparation

I have a question for any porn actress who does anal. How do you prepare your ass to be totally clean, so you can do ass to mouth without any risk? Thanks
wikipedia(*) wrote:Lewin (2001) reports that "... consumption of fresh, warm camel feces has been recommended by Bedouins as a remedy for bacterial dysentery; its efficacy (probably attributable to the antibiotic subtilisin from Bacillus subtilis) was confirmed by German soldiers in Africa during World War II."
Xenomorgue wrote:Here is a clip, demonstrating nicely how a porn actress can assist a female colleague in the preparation for anal sex:
http://www.heaven666.org/up-to-the-elbow-anal-examination-2099.php