Is the Toyota black gold the best sealant to fix this issue? Is it a one and done job (assuming done right, of course) or does it need resealing every few years assuming normal driving, no track time?

 

I did mine with the factory service manual spec stuff a couple of years ago. I just did my cam chains and had the intake manifold off to make getting the transfer tube back in place completely seamless (but it definitely took a lot more time and effort). There is zero evidence of any leaking at all now. So, it will be longer than a couple of years for sure. Probably 150k miles or so which seems to be the most common mileage we hear about. Not to say there haven't been much earlier failures, but most of us are in the ~150k mile club.