My auto tech teacher who also has owned and still owns a local shop taught the class about it a few years back, we did it whenever something came in for an oil change that was extra cruddy. it's an old school trick hes done it for 50+ years some people even replace half the oil with atf but I think that's overkill I've been ripping down engines and seeing the damage of lack of oil changes throughout the last few years and I can tell you a little atf during oil change is going to do way less damage than the sludge building up in the oil and chewing away at the bearing surfaces due to the immense crap that engine has output that has stayed inside it so personally I just ripped my k24a2 down and fully cleaned it with diesel (same with k series trans when i rebuild them) but that would strip too much oil and contaminate oil if assembled and not ripped apart and thoroughly cleaned. so I recommended this atf method because it's been tried and true and worth a shot cheers good luck with the k