Not the most efficient method but we have the tote on our water truck with a hose and valve.  We gravity flow it to fill jugs on the ground.  Put 2 gallons in each and fill sprayer through eductor.  Dad does the spraying for the most part so if he's happy it's fine with me.  As a rule we have a man moving the truck so he has time to draw up whatever chemical we need so it's sitting ready to pour in while water is pumping.  If I were spraying I think I'd start looking for better ways, but this is simple and mistakes are reduced because you can visually see a tankful worth of chemical in one spot and are more likely to notice a mistake before it happens.