Tell ya how well it cleans Over vinegar, I'm not exaggerating by saying this but a few weeks ago I went out to my storage area where I have my old 20 plus year old system that was never cleaned when I shut it down. I pulled two 40 watt pumps out of the sump, one ran the skimmer and the other was the return to the display and they were completely seized up. I filled up a pail with water and probably a heaping cup full of citric acid and tossed in a small circulating pump just to dissolve all the citric acid and then I just let the pump sit for 3 days in the solution and maybe once a day I went and gave them both a good shake and after rinsing them off I was able to pull everything apart and use a small brush just to get some of the crap that was left behind after the bath which basically was a breeze. I've tried doing vinegar over the years and honestly vinegar is a little overrated for what it does compared to citric acid.
My wife has one of these fancy coffee machines and they say to run vinegar through it which does absolutely nothing. She got on the conversation with the lady at two farm kids health store where we live and for some reason they got on the topic of coffee and one thing led to another and the lady said to take this home with you, it was a bag of citric acid. She put it in a 2 l container and dumped a bunch of the crystals into and mixed it up and ran it through her coffee machine and you wouldn't believe how well it cleans over the suggested vinegar soak and flush the machine calls for.