Rocky.... double wash in a coke/gatorade bottle or whatever with kero. First wash gets the fine grit and ***** off. You've got to shake the bottle like a martini shaker. Hard and for about 45 seconds. Let stand for 30 minutes or so. Pull it out the chain with a bent spoke or something. It will still feel gritty. Wash again in clean kero after draining off the first lot and the sediment. Let it dry in the sun, or get a hair dryer on to it to evaporate off the excess kero and before lubing. Put back on bike. One drop of lube per roller only.

Works for me.

BTW I've 10,000km out of 8sp chain. Cogs and rings are cactus with chain. But I can probably still get another 2000km. 9/10sp chains are renowned for their lack of longevity by comparison.