ATF has a lot of detergents in it, it's more corrosive but offers sufficient lubrication for idle while "cleaning".
Don't drive on it or rev the engine high.
I would read up on it and understand the process first.
91 318is - M50NV (gone)
02 WRB Subaru WRX EJ207 forged, 320 AWHP stock turbo.
85 - 325
02 325i Sedan