I'm in agreement that only petroleum jelly was added to cordite, at least until the late twenties, when that is what the "Textbook of Small Arms" says. While asphalt is a mineral oil product, any as an unintended impurity in petroleum jelly must have been minute, and the proportion of mineral jelly in cordite was small. So the chance of its being deposited in a layer from burning cordite seems non-existent, and the chances of that shifting gas erosion to a down-bore position seems not just 2x non-existent, but non-existent².
The largest naval guns are remarkably similar to rifles in velocity, pressure, and barrel length when expressed in calibres. But they differ extremely in two respects. Bore time is very much longer, and erosion a much more severe problem, with bore life being as little as 200 rounds, or down to about 70 in specialised cases such as the German Paris Gun. To some extent erosion is a result of bore time, but I think there is another cause. A flame looks opaque to the eye, but is transparent to radiated heat, and being incandescent, it does radiate very strongly. For a given inch of barrel, the area of surface receiving the heat is proportional to the bore diameter (π times diameter, to be precise). But the heat being radiated is proportional to the cube of bore diameter, a much greater figure. The large artillery bore gets hotter on the surface, and not being fired as often as a rifle, may also be cooled more quickly by the cold metal beyond.
So erosion protection by any means, even means otherwise counterproductive, assumes much greater importance in very large artillery.
We have seen a change from glazed card to strawboard disc wads over the powder, because of use in synchronised aircraft machine-guns. This was a feature of the pre-war years, in British service, as it meant guns firing between the blades of the airscrew, and as the "Textbook of Small Arms" of 1929 mentions only glazed board, I think the other came in the early 1930s. I believe the glazed cards must have spun off in a less predictable direction than the bullet, and scarred the airscrew, which may still have been wooden at the time. More brittle strawboard would have broken up. It does suggest that there was good reason not just to omit the thing altogether, and although I can find no authoritative explanation, I think it was most likely to avoid melting of the exposed core. This could only have been superficial, and is unlikely to have materially impaired accuracy, but deposition of lead may have interfered with the functioning of automatic weapons.
I referred to lanolin and perhaps its substitutes only as a lubricant inside the bullet, from which all external traces would have been removed before loading. It was probably an emulsion with water, inhibiting flashing, although such a thing as anhydrous lanolin exists, and is a constituent of a bullet lubricant recently adopted by cast bullet shooters. But I have never heard of, and I doubt, its use on the outside of a bullet in earlier times. Incidentally its use in shampoos etc. isn't as a cleaning agent, but to prevent excessive degreasing of the hair.
What I have used satisfactorily for jacketed bullet swaging is STP gasoline additive, a peculiarly sticky and non-volatile hydrocarbon which more shooters must know as case sizing lube. It costs a fraction the price of little plastic tubes from the reloading equipment makers.
Even the Textbook refers to beeswax in the cannelure as a lubricant, but there is room for very much less of it than would suffice for cast bullets. It can be argued that lead alloys need it more. But the way insufficiently large or insufficiently filled lube grooves work, is that the lube is exhausted by the time the bullet reaches the area near the muzzle, where it needs it most. None left is none left, whatever your bullet is made of - and besides, no lubricant is what nitrocellulose MkVII .303 got for many years, being sealed with a cellulose and solvent lacquer.
The air seems to have cleared around here, and long may it continue, one way or another. If the internet is anything like conversation, it is conversation in a crowded street, where anyone can listen, and anyone, with any standard of behaviour or level of interest can join in - and either be answered or have his opinions taken as true. As in many areas of science, the casual thinker can sometimes come up with an explanation or snippet of information which benefits us all. But it isn't always like that.
I wouldn't attribute too much to political change in the US, for I can't see much changing online in the next year or two. But there is no doubt that the commercial necessity, on the American gun market, to provide a home for racism, chauvinism and abusive argument, has seriously befouled our use of the internet. It is an unnatural outlet for the person forced to restrain himself in everyday life, and there are boards where there seems to be an extra rule that you don't have to obey the stated rules. Just take a look at the Sound Off and Right to Keep and Bear Arms board, to see how civilisation as we know it could end, let alone the boards they can't let even ordinarily registered members see. (I'm sure the anti-gun campaigners do, whenever their energy flags, and come away fortified.) No wonder that rubs off here. At the moment this street leads from the wrong part of town.