You have to read the original post. He isn't putting starsan in the dishwasher soap dispenser. He's putting it (properly diluted?) into the bottle with a turkey baster after rinsing them out in the dishwasher.
To the OP: if you are expecting the dishwasher to rinse oxy clean from the inside of the bottle I doubt significant water volume will be forced through the little bottle neck opening, particularly if, like me, you put he bottle necks facing down between the grids, effectively blocking operation of the wash arm. I'd recommend rinsing in a bucket of clean water (or getting a bottle jet) to get the oxy clean out. The sanitizing operation I expect when I run them through the dishwasher is the heated drying/sanitize cycle. You first have to clean any gunk out of the bottles. The easiest way is to rinse them out under the tap immediately after you empty them (you are pouring the beer into a glass to enjoy the aroma and color, aren't you!!!) Then put them away in a dust free environment untill ready to botle. On bottling day, run them through the dishwasher heated dry/sanitize cycle, no soap and no jet dry. Once they are cool and dry you can squirt some starsan in and shake it up to coat the inside and kill anything that floats in from the kitchen during bottling. You can use a turkey baster and shake it around, just be sure to pour the excess out. I use a vintator which does the same thing in one operation. A convenience but not necessary.