My experience with the “TP” filter is similar to racer72’s… Fortunately it wasn’t my car. TP disintegrates easily when wetted, even by oil.
The key here, however, as Running states, is not merely filtering out particulates, but the fact that oil does break down due to the heat, solvents (gasoline) and friction. If you change it every three to five thousand miles, it’s not given the time to break down to any large extent, and what you’re doing is removing oil contaminated by stuff that no filter can remove- fuel, extremely fine carbon, etc.
The “TP” filter, then is hardly a “suppressed” device, but rather a junk gadget that doesn’t work, just like the so-called “fuel magnets” you put on the fuel line to somehow “ionize” the gas as it passes by.
Anybody remember that old magazine ad that sold two little “ultrasonic” plates that you put in the manifuld just below the carb? They were supposed to ultrasonically vaporize the fuel so it’d burn more completely.
never heard of it? There’s probably a reason, I’m sure. 
The “200 MPG” carburetor, of course, does not and never did exist. There is only X amount of BTUs- heat energy- in a gallon of gasoline, and a reciprocating internal combustion engine can only convert Y amount of that, plus or minus, to motive force. Efficiency comes from reducing friction, reducing overall weight, and designing the engine to get more work out of that heat produced- not something a mere carburetor can do.
Even today with sophisticated fuel-injection, no commerical cal gets 200 mpg.
As for solar/geothermal/hydro/ad nauseum inventions being bought up by oil companies… why is it that oil company couldn’t also produce and/or market a solar something-or-other? Wouldn’t Shell be just as happy making money off of, say, solar cell manufacturing or patent licensing, as they are refining gasoline?
What about the so-called “gasoline pill”?
One thing I read about that, many years ago, stated that there was such a thing- you dropped it in the tank, filled it with water, and drove off.
However, the “pill” was the size of a golf ball, cost something like $90 in chemicals to make, and turned a small volume of water- a few gallons, I assumed- into something just barely flammable enough to run an old carbureted car engine.