Who’s washing machine are you putting oil rags into? Not mine!
I use old soft paper books–phone books, some insurance or election books, newspapers, to wipe brushes off first, and frequently. Those pages go into a small plastic bag, (I use the bags I bring vegetables home from the store) which when finished for the day goes into a large old metal can. I cover the papers with water and make sure the bag stays OPEN–I use 3-4 clothespins to hold it open. When it’s filled, or when garbage day comes, I make sure the papers are soaked and put it in the garbage.

Also please post suggestions for rags used with acrylics. I am guessing you would want to get them into the soapy water before the paint dries in them to get more use out of them before they are too filled with dried acrylic paint.

Paint dries pretty fast – so that might be hard to do. But I’m thinking if you wet the rag first – used a wet rag to wipe your brushes, then at the end of a session placed them in a bucket- or whatever- of soapy water as you suggest – it might work.

Would want to avoid using paper towels in the quantities you seem to be suggesting—once contaminated they would be un-recyclable. I use the moist BigWipes (which I think may be what  some here are calling shop towels) to clean my hands. I keep the used ones, they dry out quite quickly and can be used to wipe brushes (acrylic or oil), to apply paint, to ‘blend’ pastel, to wipe up spills, to…etc., etc. True, they are non recyclable, but using them in this way I have a tub of forty that I’m still less than half-way through after almost three years. I also use what in the UK are called dish cloths (about 9″ square of absorbent, loose-weave material). These also will eventually finish up in land-fill, but I bought a packet of six about five years ago and have only thrown one away and still have three clean and untouched. In this time, the amount of paper towels I would have used—and which would also have gone into land-fill—would be vast.

bongo wrote:

I would use cloth rags to wipe acrylic paint off brushes but the paint quickly dries and forms a HARD patches of paint on the rags and becomes unusable. Washing does not eliminate the hard patches of paint.

Wash the brush in a pot of water first? Then wipe; less paint, stains but doesn’t harden.

I do just the opposite.  I wipe the brush off on a paper napkin.- removing most of the paint – then swish it around in tub water (about the size of a coffee can) and wipe it again with the napkin.  This quickly removes enough paint to dip the brush in another color with little or no color contamination.

I’m switching to these napkins – https://www.amazon.com/Recycled-Single-Ply-Luncheon-Napkins-Brown/dp/B00C93AG1E?ref_=fsclp_pl_dp_2

unbleached, recycled. bio-degradable – $10. for 500.   Should easily last for a year’s + worth of painting.