Most people don't like the commercial plaster cloth material because it's "too messy", because they add too much water.
I used to put casts on people as part of my medical practice - exact same stuff - and there is an art to using it. It isn't just "dip and drip". You titrate the water you allow to absorb in the material depending on what you want to do with it.
As for "mess", I used to apply casts while in my Class A uniform. It's a skill like any other. The more you do it, the better you get.