Add in some industrial detergent as well.  Tanks are easy to clean out, it is the hoses that are tough.  2,4-D can absorb into rubber hoses, then desorb, especially overnight into your bean chemical.  We will often spray out a few gallons on a non-cropland area to flush out the booms and hoses before spraying sunflower after filling each new load or if the sprayer has sat for more than an hour or so.

If your have your own NH3 tanks and do your own maintenance on them and need to bleed the pressure off to change a valve or gauge, you can make aqua ammonia by bleeding the nurse tank into a barrel of water.