Whilst oil painting without solvents I use the following techniques to clean brushes and my hands:
A rag/cloth is incredibly useful with oil painting. Because oil paint dries so slowly you can clean most of the wet paint off your brush just by wiping the brush with a rag. This works especially well when changing between dark colours where slight colour intermixing isn’t much of an issue. When changing from a dark colour to a light I will usually clean the brush with oil (see below). You can also use the rag to wipe wet paint off the canvas.
Brush Cleaner Jar
I have two brush cleaner jars that have lids on them like the ones above. The sieve part in the bottom of the jar is extremely important. I fill them both up with linseed oil to cover the sieve. One is the ‘clean’ oil and one is the ‘dirty’ oil. When I have a brush that can’t be fully cleaned with a rag I clean as much paint off with the rag and then swish it in the oil and push it against the sieve at the bottom of the jar. You can clean in the dirty oil first and then in the clean oil. You can completely clean a brush this way. Squeeze as much oil out of the brush against the edge of the jar then wipe it with your rag. You can now continue painting with a clean brush.
One method I have been experimenting with for the past few months is first cleaning my brushes then just leaving them sitting in the clean oil jar. The brush bristles are completely covered in oil so they can’t dry out. You can theoretically leave them there indefinitely. The beauty of this method is that I don’t ever have to wash brushes in the sink (except for blending brushes which I need to have dry for the next use). It makes short painting sessions all the more enjoyable without the lengthy cleanup at the end.
One potential problem I have read about with this method is brushes bristles becoming swollen with oil that you can’t ever fully get out. I haven’t specifically noticed this problem but I can see how this could happen. I imagine this wouldn’t happen to synthetic brushes though. I am tempted to still use this method even if this does happen as the brushes that I leave in oil are fine for painting wet in wet with oil paint. It may be a bit messy to have to clean them thoroughly for acrylic painting with water, but I’ll just save some other brushes for that.
Soap and water
The other method I use to clean my brushes is soap and water. I have been using bars of vegetable soap that I buy in a health food shop but pretty much any soap should work. Just rub your brush into the soap and rinse through with water. You may need to do this a couple of times to fully clean the brush.
I also use soap and water to clean my hands at the end of a painting session.