Hoops are a popular form of wand. They can range from small to large enough to put multiple people in a bubble. Hoops can easily be made from a variety of materials that includes: hanger wire, aluminum craft wire, wire rods, PEX and similar plastic tubing, hula hoops, and more.
Dipping Trays,. A variety of items can be used for dipping trays. For small hoops, pie plates, frying pans, plastic serving trays or serving tray covers, garbage can lids, planter dip trays and the like can be used. Planter drip trays can come in very large sizes. Other popular dipping "trays" for large hoops include inflatable baby wading pools.
Moats. For Kid-in-a-Bubble, moats are often used to minimize the amount of juice needed. See Kid in a Bubble for some moat ideas.