Get a small clear plastic bottle, fruit drink, lemonade whatever, drink at least a few big sips of it more if you really want to degrade yourself then fill it back to the top with your pee and give the bottle a couple shakes to mix it up.
You then may either go out in public somewhere and enjoy your tasty beverage a little or a lot, go out some where and go to enjoy it but wind up spilling some of it on your shirt or do both.
You'll be the only one to know what you are actually doing so it is fairly low risk. If this is outside your comfort zone then no worries, if it isn't then until you get a chance to do this and report on it think about standing there in public with a clear bottle full of your own pee everyone around you as you take a sip or two from it or spill some on your shirt.
Should you not edge at least twenty times or should you cum before the timer goes off or lose track of how many times you edged or you swallow (other the the little previously addressed) or spit any of your mouthful out before you've fully completed the dare there will be a punishment.
To successfully complete this dare you must edge at least twenty times before the timer goes off and you are not to swallow or spit out any of your mouthful (as saliva builds up over time you will have to swallow tiny amounts, that is fine but your mouth should be almost unpleasantly full the whole time). If you have succesfully completed the dare you may now put a dollop of icy hot on your finger and finger yourself till you cum, you are to flush the toilet as you are cumming. I expect you to hold your mouthful until you have finished cumming as many times as youd like, you only need to flush as the first orgasm happens. Once you are done cumming you may take your head out of the toilet seat, take a comfortable position and swallow what is in your mouth, congratulations on being so willing to degrade your self for the pleasure of others and to show how sorry you are for your mistake.
You will need a timer that has an audible alarm and can be set for 20 minutes.
I would also encourage you to clean the toilet unless you feel the need for the extra humiliation
Ideally this will be done first thing in the morning, if that doesn't work with your schedule you may do this whenever time permits, I understand it may take a few days.
Ideally this will be your first pee of the day, you will pee into the toilet, catching some of it in a glass, if you deserve extreme punishment you are to take a smelly dump as well. Do not wipe when you are finished then take a mouthful of pee from the glass. Set the timer for twenty minutes, you will then lean forward placing your face in the toilet seat and have the lid lowered onto your head holding your face in the toilet. She must remain there still holding the piss in your mouth for twenty minutes during which time you are to edge at least twenty times but may not cum.