I cleaned the drivetrain of my cargobike (big panniers and such for shopping) and it had gone without serious cleaning (except the rag spin and add drops to links) for about 1500 miles. Of course, the only lube it had seen was 3-in-1 oil, which is crap. Removed the chain with my chain tool, the front rings, and the sprockets on the derailleur. Took it all to the bathtub (apartment living, wall to wall damn carpets everywhere,) and went to work with citrus cleaner and brushes. Damn that was a job and a half. At some point I was playing with the idea of getting a hammer and chisel to get the damn oil and crud off, sat like cement. After several hard cleaning nights, redoing over and over to get it really good, the sprockets are red again, and the chain is if not bright and shiny, at least clean. I could have filled a car engine with the oil, and a family size litterbox with the sand and grit.
Once the cleanup was done, I used Tri-Flow on the chain, and it's like new. I am thinking of getting a chain cleaner gizmo and use it every week just to snazz it up instead of doing another dismantling job. Oh, and I'd sooner put my noogies on the table and bash them with my mallet before I put another drop of oil on my bikes, it's all Tri-Flow from here on out.
Sverre.