Is draining it 3X something you've read on a forum? That's not something a dealer or repair shop would do.
They would most likely do a reverse flush, or just drop the sump and change or clean the filter.
Draining 3X just to get the remaining one quart left in the converter is overkill and wastes a lot of ATF. It's really a waste if the pan isn't dropped and the filter not changed.
It would be like washing one hand 3x but not the other.
There are drains on a few torque converters, not many though. Most don't have them, that's why it's best to change often.
If you really want to lengthen the life of both the fluid and transmission. Get a trans cooler installed.
Good luck and be careful out there.