Had one for several years so its not the latest model which I think can heat the water tank as well. Ours you fill one large tank with warm water and another small one with the cleaning fluid. Seems to work a charm and has been passed around the family several times. Ours is similar to this one click here. Can't say that we have used it a lot but others in the family have thrashed it and have said that it does a good job.
I have the model described by chub_tor and have found it to be excellent.
One tip though...clean it thoroughly after use because the cleaning solution will turn sticky and clog the pipes if left unused for some time. Stripping it down and repairing it is not for the faint hearted. I am experienced in this task!!