[Broncofan]

Probably an easier, lest costly way:
When you change your own oll, after removing oil drain plug and filter, wait a couple hours for it to fully drain. Then, before you put back the drain plug, pour into your oil intake maybe a half or so quart of new oil. (Lots of cars take 4.5 quarts or 5.5 quarts). Wait for that to drip thorough then put you plug and oil filter on.
If you have someone helping you, and you are down below, you can see the new oil "push out" the dirty old oil which was not removed. Its cheaper and faster. You can skip the waiting, too, but its better to wait until your oil all drains down. The idea is you have more nearly 100 percent new oil and only a very small portion of used oil inside your engine.

 

[Broncofan]

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.

 

[Broncofan]

Trunkmonkey: Great idea! I wish I would have thought of using air pressure with a can..its a better idea than mine, as it would not waste clean oil.
What I tried to do (to prevent waste of clean oil) is to "recycle" the oil..its not real dirty like dirty oil, but not completely clean, either, as it has been mixed up with old dirty oil. But it works in an oil can, which I use for lubricating hinges, or anything that needs a few drops of oil. Sure, WD40 spray has some advantages to "the old fashioned oil can" you rarely see mechanics use any more, but there are advantages, too, to the old fashioned oil can, we used often on the farm. Heck, nowadays, mechanics often dont even know what a grease gun is. My son bought a new Kabota tractor, however, and it has many grease zerks, which need greased frequently..or else. Its rather unclear to me why a tractor would need grease zerks, while virtually all new cars have no grease zerks. They are all "sealed". So, why would a tractor have grease zerks and a car not? We also dont "pack" wheel bearings anymore..which we always used to do. My father told the story of his 32 Ford. He said he ran it to fast on low oil, and it started knocking. So, he took the oil pan off, and took a file and "filed down" the end caps of the bearings (making it close slightly smaller), put the used oil back in, and drove off...no more knocking.
There is some truth to Henry Fords statement that "the 32 Ford" is perfect, no research is needed, you cant improve it. While it has been massively improved in many ways, I actually tried "filing down the end cap bearings" on my 55 chevy in line 6 cylinder that was knocking after I inserted new bearings. I had taken sandpaper and sanded off the grooves on the crankshaft, somewhat, and put it back together. The engine started and maybe ran a mile before, when it threw a rod, you knew it was done. I knew then the old school "filing the bearing caps" to stop your car from knocking was over.

Mostly, they dont seem to rebuild (remanufacture) most engines anymore. Yea, you can still rebuild an old Chevy 327, or even a six cylinder. But, you probably wont get a good result rebuilding your 4 cylinder 2005 Nissan or Toyota. Modern engines are manufactured by massive machines with very close tolerances that is exceptionally difficult to duplicate in many/most machine shops. Engines have become disposable, sadly, and are not designed to be rebuilt.