I am passing them now, after having gone through a few. I do still make stupid mistakes more than I would have in my youth. Four weeks drilling would definitely more than do it.
I think the bigger problem is none of the other skills I have seem to even matter for Google/Amazon/Facebook hiring. I would rather practice those skills and find niche openings which value people like me than do prep for a broken process. Plus I have family, consulting, etc, so I don't want to just drill. I'm not desperate. I could be wrong (no offers yet, but just started on sites so don't expect any yet) but I think I have better options elsewhere.
If I weren't actively looking, I wouldn't even consider those types of jobs, and this is the first time in my life actively looking. In other words, Google has no chance of poaching someone like me. I think the word for that is implicit bias or disparate impact.
Boston area.