Yes, I agree. I see no problem with what he wants to do, just wanted to point out the detergency thing is a common misconception. BF: People do use it for decarbonizing but that has nothing to do with it's detergency. If they're pouring in their crankcases they're wasting their time and money. Feel free to persue the MSDS of any ATF fluid. I don't suggest solvent flushing an engine but if you're going to do it a quart of kerosene beats just about anything. If you really want to clean an engine the right way use a product called Auto-RX. One of the few "snake oils" out there that really works.
edit: Ok, here's a bit. See myth #12:
http://tinyurl.com/j2kng
There are other oil industry sites that debunk this myth.
Here's a virgin oil detergent analysis of both Moble 1 motor oil and Moble 1 ATF:
M1 ATF:
Calcium 230
Magnesium 1
Phosphorus 284
Zinc 41
Now compare that to M1 motor oil:
Calcium 2517
Magnisium 428
Phosphorus 970
Zinc 1004
In short the oil has way more detergency so how is ATF going to clean better? It's a glorified hydraulic fluid, a class of products that aren't known for, and have no need of, high detergency. They do have anti-oxidants, thermal stabilzers, mild dispersants and some other stuff in the add pack but high detergency they aren't.