I know I'm not doing the same as you guys but,,,, (dirt biker at heart, old ways die hard),,,,, Dirty chain gets WD-40. Rub down next, then soaked in chain wax or what ever is your lube of choice is( I have tried them all), then a rub down again. Go 4 a ride (heat), when back, rub down again. I do not let the chain soak in WD-40, lol. Like reported above WD is a abrasive. WD-40 is a Great FAST cleaner, this is why we are useing it in the first place, correct. No ? If you dry off the chain and lube it straight away, no harm no foul. Leave WD-40 on the chain or use it as a lube alone and it cuts when mixed with sand & dirt.
Is this the way to get 40 tho miles out of a chain ????????????????? I'm not the guy to give that info, slack in the links she's in the dumpster. Miles mean nothing. My 2 cents