Back in my fossil age ('70s) I used to use gasoline in three consecutive cans, shaking the chain in each until no more grit came off. Was a stinky mess. But I used to use oil lube then, which would stick grit to the chain. Now, three decades plus on, I don't see the need to do this, because the lubes I use don't attract grit a tenth as much. Needless to say, I don't ride offroad. With the passage of time chain technology has improved immensely. Tolerances are closer, leaving less space for foreign matter, and the metals are harder.