Article 3.1: Wash Your Hands, But Not Your Feet
When washing, make sure to scrub for at least 20 seconds. Any less, and you're not really washing. Any more, and you'll be scrubbing away your career.
Article 3.2: Toilet Paper Etiquette
Do not, I repeat, DO NOT, leave toilet paper for your colleagues. It's not a gift, nor a loan, nor a communal resource. It's a solo operation.
Article 3.3: Showering with Colleagues
Showering with colleagues is only acceptable if you're both wearing matching swimsuits. Otherwise, it's just weird.
Article 3.4: Bathroom Noise Levels
Keep your singing, shouting, and general merriment to a minimum. The deputy in the stall next to you is trying to concentrate.
Appendix: Bathroom Emergency Procedures