[Locked Puppy]

This puppy would like a medium to hard challenge. Preferably not involving workouts.

Drinking pee and extending the time maybe for failure, other punishments you prefer are also fine instead or in combination.

Something hidden public, or covert public in the process (for either drinking the failure, or what you want to come up with).

I have available: Water, Tea, Coco (can't drink pure milk), Beer (can safely drink two bottles within two hours), Coffee

I do live in a village though have a train ride into a larger town ahead of me tomorrow. The ride takes about one hour each direction, and I have shopping business in town for about an hour as well.
The train usually has a lockable toilet space. There are public toilets at the city train station.