Been using a chain scrubber for years, tried the Park Tool CM-5.3 cyclone on a buddy's bike and now I feel dumb
Spent 12 years doing the on-bike chain clean with a toothbrush and degreaser and always thought it was good enough until I ran his chain through the cyclone tool and watched the grit come off in like 90 seconds, so is there any real reason to keep doing it the slow way besides habit?