If your diapers have a urine residue, the easiest way to fix them is to run several hot water washes with as much water as you can add to the machine. (thinking-about-cloth-diapers.com)
Now, I just run the regular hot water wash twice after they go through with detergent. (theclothdiaperwhisperer.com)
I do a load of hot water wash every other day and it adds zero time to life. (children.costhelper.com)