I totally get that comment!
a) machined washes used to cause my 2003 Expy "door ajar" problem so that ended about 10 years ago.
b) machined washes dont get my 2014 Expy clean
(and DeltaSonic is a top quality "contact" carwash)
I'll run a machined wash on the 2014 after a roadtrip to get underneath and avoid mud in driveway. Then I come home and hand wash. If its above freezing. I wear rain gear and big rubber gloves when its 35 degrees. I also get down on the ground and extensively spray water everywhere I can get to underneath to flush the salt & grit away. Dont know how effective that will be long term in avoiding rust, but YGDWYGD.
But - to each his own.
Ya gotta do what ya gotta do