actually grease over balls has great efect in stopping chain fires if your balls are under sized. tested it with a batch of .440 balls. agreed that not necessary for chain fires with .454 balls but I do find that no lube equals harder to clean.
That would be a case of pushing to an extreme and then saying lube works. Well, sort of. Any failure in the lube and its coverage and its a chain fire for sure. The correct approach is not to have to add stuff to try to prevent a guaranteed result, ie, use the right sized ball.
I go with the right size ball (.454) and as I buy mine, no sprue.
I also do not use lube over ball or conical and I have had not chain fires. I do use a felt pad if I use a .451 ball (like to play with things) . Now I am a low end user, maybe 1000 shots so far. I think its a fair sampling but more is better.
At .451 according to the stuff I look at, you are into the upper range of iffy. At a guess .448 is getting into close of it not virtually a guarantee of a chain fire.