The smoke-killing sand can be left for 2 days at a time. According to the relevant information query, smoke sand is a very popular product on the Internet recently. We only need to pour an appropriate amount of water into the ashtray, and then pour the smoke extinguishing sand into the water, so that the water in the tank will solidify. , we only need to insert the finished cigarette into it, and it can be stored for 2 days.