I've only developed one roll of Kodachrome 200 in B&W chemistry; I'd have to look up the development details, but I do remember I also used water as stop bath, and refreshed this several times, as there was indeed a lot of colour in it. After fixing, washing and some more washing (and then some), I was left with something that doesn't look too bad on the light table, but without light falling through it, it is hard to discern this film from undeveloped film.
So, despite all the washing and even moving the wet film between the fingers to remove some more black stuff, I think there's still "something not right". Still, it was only one roll, with no special shots, so I didn't investigate any further. Didn't try to print or scan (I apologise for using that term) yet.
If you want, I can look up some more details in my notes. But then again, K200 is not KR64.