Abstract: An accessory for use in a vacuum cleaner or a vacuum-cleaning conduit for collecting and holding liquid sucked up by the vacuum cleaner, comprising: a container having a reservoir for holding the liquid, a removable cover for said container and extending substantially horizontally thereover, means for dividing said container into said reservoir and a chamber above said reservoir and having a substantially horizontally extending plate, an inlet fitting connected to said cover for connecting the interior of sand reservoir to a hose leading to the suction nozzle of the vacuum cleaner or a vacuum cleaning conduit, said inlet fitting including a pipe extending vertically and having a lower end portion extending into said reservoir, an outlet fitting in said cover for connection to a hose leading to the body of the vacuum cleaner or vacuum-cleaning conduit and communicating with said chamber, at least one passage in said plate between said chamber and said reservoir, and a float-controlled valve including a float v