The quick easy flush I described, above, wont "clear sludge", per se, but a constant wash in the cleanest oil possible, will. This is what this intends to accomplish by this simple method to make sure as much as possible of the "dirty" oil is flushed at oil change. When you pour in clean oil, it becomes slightly diluted with dirty oil, left in your engine at oil change, at your new oil change. Using the method I described, means there will be less dirty oil to dilute the clean oil. Its kinda like trying to wipe something clean with a very dirty soiled oily wrag..it does not work that well, but instead spreads dirt all over the surfaces you intend to clean. Instead, wipe it off with as clean a wrag as possible.
In the same way, the method, above, cleans at least SOME of the dirty oil left in your engine at oil change. Disassembling the engine, of course, would allow a full sludge removal.
A family member, with extensive motor cycle racing experience, recommends Amsoil. I did check the Amsoil website, where the sludge removal is documented, by actual engines broken down after use, along with otther testing procedures.
I found no such oil testing results at Marvel Mystery Oil. While test results can be manipulated, these third party oil tests did demonstrate that my cousin's opinion on the value of Amsoil was spot on.
Instead of relying upon anecdotal evidence "My uncle said this brand of oil was best, so it has to be the best", I prefer documented comparison testing. While car companies dont recommend oil additives, such as Marvel Mystery oil, Amsoil products are good enough so that you warranty is still in force after using Amsoil at oil change instead of other brands. Indeed, the lubrication engineers which work for the car companies, review the tests. As far as I know, none of the major car companies recommend oil additives, but do provide lubricant quality specificiations, supported by testing.
For my vehicles, I will do what the engineers recommend, as opposed to ancedotal evidence. For that reason, I dont use oil additives.