The invention relates to an autonomous device (30, 114, 214) for spraying a medium to be sprayed, comprising: a control tank (34, 116)； a valve (32, 118) that can switch from a closed position to an open position and vice versa, according to the filling level of the control tank (34, 116)； and a porous ceramic wall (36, 120, 220) that can be in contact with the medium to be sprayed and separates the control tank (34, 116) from said medium to be sprayed, the ceramic being structured so as to drain a spray liquid between the medium to be sprayed and the control tank (34, 116). The invention also relates to an autonomous device for controlling the spraying.
