A ballooned cleaning device for use with an ETT or tracheostomy ventilation tube 60, a ventilator machine 900, a source(s) 602 of pressurized liquid and a source(s) of suctioning 603, the cleaning device comprising: a. a tube-connector assembly 158 for connecting the ventilation tube 60 to the ventilator machine 900, in a substantially air-tight manner; b. an elongate, flexible, main body 210 that is insertable through the tube-connector assembly 158 into the ventilation tube 60 to form an interstitial region outside of the main body 210 within ventilation tube 60; c. a balloon 588 mounted to the main body 210 at a location in the distal half of the main body and inflatable into contact with an inner surface 201 of the ventilation tube 60; d. one or more liquid-delivery lumen(s) 520 arranged within or along the elongated main body, and operative to transport pressurized liquid received from pressurized liquid source(s) outside of the ventilation tube 60, into a proximal portion 774 of the interstitial region that is proximal of the balloon 588 so that the transported liquid enters the proximal portion 774 via liquid delivery orifice(s) 525 located on or mechanically coupled to the main body 210; e. suction lumen(s) 530 arranged within or along the main body 210, and operative to convey negative pressure from suction source(s) 603 predominantly into the proximal portion 774 of interstitial region via suction orifice(s) 440 when balloon 588 is inflated into contact, suction orifice(s) 440 being open to the proximal portion 774 and mechanically coupled to the main body 210; f. a suction port 830 connectable to the suction source(s) 603 for mediating a connection between the suction source and the suction lumen(s); and g. a pliable sleeve 610 around at least a portion of the main body 210 in locations proximal to the tube-connector assembly 158 and distal to the suction port 830 to inhibit contamination, wherein at least one of the fluid delivery orifice(s) 525 is a hole in the boundary- forming balloon 588 so that the boundary-forming balloon 588 is leaky. a. a tube-connector assembly 158 for connecting the ventilation tube 60 to the ventilator machine 900, in a substantially air-tight manner; b. an elongate, flexible, main body 210 that is insertable through the tube-connector assembly 158 into the ventilation tube 60 to form an interstitial region outside of the main body 210 within ventilation tube 60; c. a balloon 588 mounted to the main body 210 at a location in the distal half of the main body and inflatable into contact with an inner surface 201 of the ventilation tube 60; d. one or more liquid-delivery lumen(s) 520 arranged within or along the elongated main body, and operative to transport pressurized liquid received from pressurized liquid source(s) outside of the ventilation tube 60, into a proximal portion 774 of the interstitial region that is proximal of the balloon 588 so that the transported liquid enters the proximal portion 774 via liquid delivery orifice(s) 525 located on or mechanically coupled to the main body 210; e. suction lumen(s) 530 arranged within or along the main body 210, and operative to convey negative pressure from suction source(s) 603 predominantly into the proximal portion 774 of interstitial region via suction orifice(s) 440 when balloon 588 is inflated into contact, suction orifice(s) 440 being open to the proximal portion 774 and mechanically coupled to the main body 210; f. a suction port 830 connectable to the suction source(s) 603 for mediating a connection between the suction source and the suction lumen(s); and g. a pliable sleeve 610 around at least a portion of the main body 210 in locations proximal to the tube-connector assembly 158 and distal to the suction port 830 to inhibit contamination,