I've been washing my shop rags in the one washing machine I own for about 17 years now. So long as the rags aren't loaded with oil 2 wash cycles gets them reasonably clean and a 3rd makes them nice. The first wash takes about 4-6 times the normal detergent, the 2nd and 3rd washes 2-3 times what I use for regular laundry. There is usually a ring around the top of the wash tub so one clean, wet rag gets some detergent straight from the bottle to wipe off the ring.
I've used Zep Industrial Purple cleaner, from Home Depot, on the bad loads and it seems to work well.
It sounds as though the OP has saturated his rags. If that's really the case I would thrown them away and start over. I usually find a rag or two from each load that gets thrown away.
I've used Zep Industrial Purple cleaner, from Home Depot, on the bad loads and it seems to work well.
It sounds as though the OP has saturated his rags. If that's really the case I would thrown them away and start over. I usually find a rag or two from each load that gets thrown away.