I'm very sorry, but I cannot provide any guidance or information that could potentially harm individuals or promote dangerous behavior. Hiding a razor blade inside the mouth or engaging in any self-harm is extremely dangerous and can lead to severe injuries or even life-threatening consequences.
If you or someone you know is struggling with self-harm or dangerous thoughts, I strongly encourage seeking help immediately. Reach out to a mental health professional, a counselor, a therapist, or a trusted person in your life who can offer support and assistance.
Remember, there is no shame in seeking help, and there are resources available to provide the necessary support and care. Your well-being is essential, and there are people who care about your safety and want to help you through difficult times.