People are doing what they will always do... reading and digesting selectively what they WANT to read and digest.
LONG (years) ago I stated Thermochill rads shouldn't need flushing with anything but water, but if folks ain't happy with that then to follow recommended methods elsewhere on the net as we haven't done any investigations ourselves on the issue, as have never had the need to.
Vinegar is FINE to use for cleaning your rad, as long as you don't leave it in there for days on end. A few hours then a rinse is absolutely fine. However, that doesn't change the fact that it's unnecessary and hotwater will do the job. Vinegar on it's own WILL NOT cause any longterm damage to the rad. It will cause oxidisation of the surface, which when mixed with elements from solder and flux may result in a black tarnish... once done with the vinegar you should be flushing with distilled anyways to remove this oxidisation, and thus remove the "dirty" layer... this is the whole point of cleaning - to strip a fractionally thin surface layer away thus leaving a clean layer beneath... and because vinegar is actually doing this you're all complaining??
Also bear in mind, I only discovered we'd shifted to water-based flux last week...
Even now, after I've stated that folks only need to use hot water to flush OUR rads with, folks are STILL debating "what can do it better"... "should I use hot water AND vinegar?"... so what the hell difference does it make what I say?? You guys'll do what you always do and take it one step further, so what was the point of me saying it in the first place?
You ask what you should do, folks tell you, y'all do whatever you wanna do regardless... just as long as there's a manufacturer there to blame at the end of it all, who cares?? The mentalities displayed here are the reasons why very few other manufacturers are present to offer their input on forums such as this. The only reason I'm here is because I was a member here LONG before ThermoChill and my involvement in such ever existed, and planned to remain so as why should I sacrifice a personal interest and hobby for work??
There are many products out there DESIGNED for flushing and cleaning radiators. These are the right tools for the job. However, these will add further contaminants to your loop. So, you can't use the stuff DESIGNED to do the job - which is the stuff the entire radiator industry would say to use and which is the only stuff anyone can really RECOMMEND to do the job, so anything else is OPINION or recommendation. If you want to do it right take your pick. I won't be advising further on the issue.
DO WHATEVER YOU WANT TO DO.