Well, if you washed the yeast correctly, and have let it sit in your fridge for a week or more, you don't have 4x16 ounce jars full of yeast. You have 4x16 ounce jars full of water with about an ounce of dormant yeast settled on the bottom.
Your best bet is to make a starter - no stir plate is required for a starter! A stir plate only allows you to make a get away with smaller starters, really. And they look cool. Make up about 1.5L to 2L of 1.030 to 1.040 wort with some extra light DME, decant off most of the water in your pint jar, then shake up what's left and dump that into your starter (Growlers work pretty well for 1.5L starters, if you don't have anything better). Shake that thing up every time you see it for a day or two, then you should be ready to pitch that into your wort.
The starter's really pretty key because, depending on how long those jars have sat in your fridge, the yeast has gone dormant and a lot of those cells may no longer be viable. The starter will help the yeast wake up and build back up a good population of viable cells prior to getting pitched into your wort.