Hold it for 2 days, then take a laxative and go out. Walk for 10 minutes and find a random shop (when I fantasized about this, I was thinking about some newsstand or a bookstall). Anyway, while you're there, you must relax. You're not allowed to resist to the pressure. I'm not saying you must push, but if it wants to come out, you can't do anything. After you've bought something and you're out of the shop, you can regain control. Walk back to your home and 5 minutes before stop at another shop and do the same. You must stay in the shops for at least 2 minutes. (You can also just watch around, I won't force you to buy something :P ). In case you succeed at being clean, you must relax as well when you'll be in front of your house door (if you live in a palace, you must relax at the main entrance and on the stairs, if there are). I hope your laxatives are enough effective
Let me know if it's doable for you
