I was doing some reading about a certain Toyota auto tranny maintenance. Apparently when you change the fluid at the recommended 90,000k mark, you are way behind the 8-ball, and every "change" of fluid only drains 1/3 of the ATF because the other 2/3 are in the torque converter and is not drained. So they are recommending me to change 1/3 of the fluid every 90,000ks. ??!!

What would you do? 

AND say if you have a CVT does a change of fluid change the entire capacity or does it also have some pandora box that hides fluid that cannot be touched?

Thanks