Transmission flush

[Toolmanmike]

Yes.
I work as a service advisor fopr 20 years in a 16 bay shop.
I have two licenced mechanics with 75 years combined experience.
We also concur to your tranny expert's advice.
There are many transmissions that will fail after a flush if never been serviced at regular intervals.
We prefer the "splash n dash" method of dropping the pan,change the filter over using the flush machine..
The machine can loosen up any particles that can and will cause problems.

Exactly. I was a serv. adv. for 13 years and I changed careers just about the time the flush machines came on the market. Then I became a MAC Tool dealer and sold them for 28 years. I sold very few though.