Please choose the correct ending to complete the given sentence: Pets and Animals: [header] How to clean your dog's toothbrush [title] Use a separate toothbrush for each dog. [step] After brushing your dog's teeth, rinse the toothbrush under warm water. Remove any toothpaste, food particles, and debris from the toothbrush with your thumb.

Ending1: You can also use a toothpick to remove smaller particles. [title] Rinse the toothbrush after each use. Ending2: [substeps] Taking the brush into hot water can potentially damage the toothbrush. [title] Make sure your dog will use a seat. Ending3: Gently wipe down the bristles with the toothbrush until all traces of toothpaste are gone. [substeps] If you use a toothbrush with a plastic handle, make sure to replace it before handling it again. Ending4: You do not want to leave any residue in the brush while it is being cleaned. [substeps] This method can be very messy and requires a regular brush.

Answer format: ending1/ending2/ending3/ending4