Find a place where they have open showers (no walls). Wait until it is completely empty. Then, go into the toilet and edge yourself. After that, you can either choose to go to the showers and masturbate until you come, or, if for some reason you don't want to (for example there is someone else and you dont want to be seen), go back into the toilet and edge again. Repeat until you have managed to come. If you fail after 5 edges, you can choose to stop the dare, but then you can't touch yourself for 2 days
Have fun!
It is a bit of a complicated dare but I hope you enjoy it! If you have any feedback, I'd love to hear it