If you're just using it for hand washing, you probably don't need an ultra-concentrated solution. A very small amount of detergent goes a long way. (Think about it - what would you do with an ultra-concentrated solution? Probably squirt a small amount on the glassware and then add water.)
What I've seen done is to make your "dilute" solution of Alconox, put it in a squirt bottle, and then use a healthy squirt of it when washing. In fact, you probably find you don't even need a healthy squirt of it. A small amount of even the dilute solution is fine.
The approaches I've seen have been rather cavalier - basically just throwing a bunch of the powder in the squirt bottle and filling it with water. You quickly get a sense of how much will dissolve, and if you use a squirt bottle with a drop tube that doesn't go all the way to the bottom, you don't need to worry if not all of it dissolves.
Alternatively, as you you seem the fastidious type, you can fill another (non-squirt) bottle partway with Alconox, the rest of the way with water and let that sit (perhaps with occasional mixing). This should give you a saturated Alconox solution, which you can use to fill the squirt bottle, being careful not to transfer residual powder from the bottle. Then you can add more Alconox powder and water to the stock bottle, let dissolve, and you should be ready for the next time.
Again, this may only give you a 10-20% solution of Alconox in water, but that should be more than sufficiently concentrated for most usages.