I use something like this to clean my brushes, and all the sediment sinks to the bottom:

http://www.jerrysartarama.com/discount-art-supplies/brush-washers-and-cleaning-supplies/brush-washers/da-vinci-air-tight-brush-washer.htm

But, most of the time I’ll use a separate brush for each color, but when I clean my brushes between colors or at the end I use the thing above

I use a small, 12-oz., metal, coffee can, into the bottom of which I place a round piece of hardware cloth, with the edges bent down about 1/4 of an inch, so as to keep it off the bottom of the can, and allow about a quarter inch of space for sediment to settle.

“Hardware cloth” is that metal mesh that looks a bit like fine, chicken wire, but it is a bit stiffer, with a square weave.

I add enough Odorless Mineral Spirits to the can so as to have the level of the liquid at least 1/2 inch above the mesh.

Between colors, when necessary, I swish my brush across the screen in the bottom of the can and then I wipe my brush with a paper towel. When changing from a dark to a light color, I will often swish my brush in the solvent, and then squeeze the bristles from the ferrule toward the tip with the paper towel. When simply doing a rough cleaning of the brush just to remove excess paint, I keep a folded, paper towel, bulldog-clipped to the lower edge of my palette, which I hold in my hand. For a cursory cleaning, after swishing in the solvent, I just wipe my brush across that folded paper towel.

I am always very conscious of keeping as my cleaning solvent, an ingredient that is very compatible with my oil paint. I avoid using non-drying oils for this cleaning, and only use solvents that are compatible with my paint.

I, on the other hand, will paint for hours with one brush, it certainly doesn’t take that long to wipe it off on a paper towel (to get the majority of the paint off), swish it in solvent, wipe it on a different ‘solvent rag’ and continue.

I have precious little room to paint, and don’t like the thought of a dozen or so brushes, all wet with different colors, being around my couch (painting chair).

The solvent may get dirty a little but is still clean enough to not contaminate colors for a good while – I paint a good 20-25 hours a week and change my solvent jar every two weeks or so.

As for saving time using many brushes, maybe so, but I only have to clean a couple at the end of a painting session, not a dozen and a half:).

I am new to this oil painting thing as well so I have a limited collection of brushes and to the solvent/towel clean between colors myself. Only thing I might add that I didn’t see above is I keep a couple knives around to grab more white for the mixture/color I’m working with…it isn’t a bother to me to grad for a knife that can be wiped completely clean with paper towel to avoid messing my white and having to also clean a brush.

I forgot how expensive that brush cleaner was! But I bought it 3 years ago and it still works great. I like that it seals and I can use the same solvent for weeks before changing it out. I probably made up the cost on what I saved in solvents.

No, NP don’t throw them in the trash..first immerse them in water or use a special fireproof metal container and then if they include solvents or heavy metals dispose as hazardous waste.