Product review (5 stars): Great for Haier portable dryers!
I own a Haier HLP140E portable dryer and bought this to help with using inside. I keep the bucket with water in it as directed  and place on a window sill (either open or closed) and it works perfectly. My dryer doesn't produce a lot of lint at all so cleaning this out is maybe once every 2 months. With the window closed, for me, it doesn't create a sauna but I do have a larger kitchen in my apartment.

Highly recommended for indoor dryers, especially the Haier HLP140E.