5g buckets and a good bit of water. If you're trying to save the bacteria (it's possible), you have to use saltwater. Other than that, I put a few inches in the bottom of a 5g bucket, add some water, swirl and dump. Do that a few time until the water is mostly clean and dump it out for drying. I've done this a few times over the years and the biggest issue is getting the stuff dry. Especially right now with all the pollen. The most effective way I've discovered is to use a large pan or sheet and spread it out as much as possible. I have some generic cat litter boxes that I used for this purpose. Usually if I'm just going to store the sand, I'll clean it over the course of a few weeks.