Transmission flush harmful?

I have heard conflicting opinions on whether a transmission flush harms an
automatic transmission or not. I am considering a flush and replacement of
fluid for a 98 Accord. It may have some non-Honda ATF and is shifting a bit
rough.

Any thoughts?

 

Don't "flush" per se; just drain, refill, drive a mile or two, drain,
refill, drive a mile or two, and keep doing that for 5 or 6 times.
You'll get the non-Honda stuff out that way. (By the way, this is the
factory recommended procedure for my Odyssey minivan for the 45K
changing of the transmission fluid.)

A 94 Lexus came into my hands about a year ago. Turned out the tranny
needed completely rebuilt. I looked into the meticulously kept records;
it seems that up until two years prior, the owner had taken it
exclusively to his Lexus dealer. But since then, it went to a corner
gas station--who had done a "special" transmission flush and fill, with
some sort of additive "for long life". Yeah, right--I don't think so.
I think he ruined the tranny.

Aamco got my business, and I'm a happy man now.