we're using a 5% concentration of citric acid to descale our machines and our bicarb loop. I use the bicarb mixer and make a 25 gallon batch, 24 gal RO + 9 scoops of CA. The scoop is a 500 mL scoop, but this is approximately the same as 500 g of the CA. RPC has a concentration mixing chart.
for the machines, I use the 2.5 gallon acetic acid jugs. I drilled a hole in the top opposite the white connector and put a red wand connector in the hole. I use the bicarb mixer to make a 25 or 50 gallon batch, depending on if I'm descaling the loop that day, and fill the jugs from the tank.
As far as cleaning the outside of the machines, it's ok for removing deposits and scale, but it does not disinfect. 1% bleach is still recommended for that.
Are you disinfecting the inside of the mach,or cleaning the outside cabinent? 
