shop vac
Shop vacs are often called wet/dry vacs because they also suck up water. If you have an application that can use one, then YES you need one. They make small ones and large ones. Which you need depends on how MUCH stuff you are picking up, and how much room you have to store it. If you go for the best, a metal one, be advised that they develop a lot of static electricity and you will get zapped everytime you touch the tank, unless it is grounded, and the ground plug on the cord does not usally drain the static electricity.