Painting without the smell of solvents is attractive to many oil painters. The smell of turpentine can be hard for the artist nose to tolerate, while some people are allergic to dried damar varnish because of the crystals.
Damar varnish and turpentine are used by many oil painters for glazing. Paintings glazed with this method have a chance of yellowing after many years. Walnut oil can be used to thin the paint to a translucent color and can be used for glazing.
Walnut oil has the advantage of not becoming darkened as fast as linseed oil does.The darkening is caused by oxidation of the paint film. This is another good reason to use walnut oil.
Though I haven't tried walnut based paints and walnut oil for glazing, I've read about it and may give it a try. I did start using water based oils years ago. It sounds like the walnut oil based paints have the cleanup advantage of water based oils. Easy.
To clean brushes when using walnut oil based paints use walnut oil and wipe them off, then clean with a soap and put a little of the oil on the brushes. Clean the surfeit oil off with a rag.
I hope this oil painting idea helps oil painters that haven't heard of walnut oil based paints.