I've had the cascade washer for about 20/24 years, it is a great tool, but it implies that you have ample supply of fresh running water. Whilst it is designed for the Jobo film tanks, it will fit Paterson tanks perfectly. I have both in my darkroom and the cascade washer works equally well on either tank system.
The trick with the Jobo cascade thing is the little hole in the side, which allows air to be pulled in as the water flows past. This adds turbulence to the wash and effectively massages the film somewhat and also pushes any bubbles sticking to the side of the film away.
You have to have the water flowing so that the water level inside the transparent nozzle, is between the two red lines. Below that, there is not enough pressure therefore no bubbles, above the lines and you are wasting water and once again no bubbles, or very little bubbles.
The basics are that with the cascade attached, you should have quite well washed film in approximately 5 minutes of usage.
It does do what Jobo says it should do, however if you have to pay a premium, I would think twice before purchasing one.
These days with sparse water in a lot of the planet, inversion washing is what a lot of people appear to be doing. I hand invert myself, instead of using my Jobo cascade attachment.
Having used squeegees on film in a lithographic environment for many years, then tried to use them on normal photographic film like you will be using, I would suggest using a very good cleaning technique to ensure that the rubber blades are really clean. The slightest bit of foreign matter and you will have scratched film.
Ilford and Kodak sell wetting agent products that help water sheet off once you hang it up. These products really do help film to dry, water mark free.
Mick.