Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to clean a bubbler pipe [title] Drain the dirty water out of the pipe. [step] Before you begin cleaning your smoking pipe, you'll want to make sure it's completely empty. Pour the used water down the sink and shake any remaining moisture out of the pipe.

Ending1: Set the pipe aside until you're clean. [substeps] Keep in mind this step is optional. Ending2: [title] Mix the water with a spoon to form a paste. [step] Once the pipes are completely clean, fill a resealable plastic bag with water and add a few drops of your favorite essential oil (rubbing alcohol or tea tree oil). Ending3: Remove the stem and set it aside for now-you'll be cleaning this separately later. [substeps] It's a good idea to always refill your pipe with fresh water after every use. Ending4: By giving it a few hours to drain, you'll be able to clean properly. [substeps] During this time, you'll need to replace the pipe.

Answer format: ending1/ending2/ending3/ending4