Product review (5 stars): Inexpensive alternative
This is an inexpensive alternative to an expensive problem.  I had a portable washer & dryer and needed a way to vent the dryer without drilling holes in the walls.  This worked perfectly.  Simply attach the hose to the dryer, fill the plastic tub with some water, and the dryer will vent right into the room without leaving dust and lint everywhere because the water traps it in the tub.  Clean the tub between each use and you're good to go.  This is definitely a great value and an ingenious way to solve a little problem that some of us have!