The Dryden Aqua products are a "system" of chemicals and equipment meant to work together in unison to produce a water body that can remain clean at low FC levels (typically less than 0.7ppm). They are a Scottish company that sells mostly into the European market where CYA use is heavily regulated. Their system can work but you can't just take the components of it and expect the same results.
The ACO chemical is most likely titanium dioxide nanoparticles that, due to their size, stay suspended and dispersed into solution. TiO2 strongly absorbs UV radiation and is often used as a catalyst material to enhance UV photolysis of waste water chemicals. In a swimming pool at low concentrations, it would act to block the transmission off UV light in the bulk of the water volume. While the UV absorbing properties would save on chlorine loss, it has no effect of chlorine chemistry, meaning, it has no buffering or reserve effect. In the Dryden Aqua system, pool water is heavily filtered using a constant injection of flocculant into the input side of the water stream and then a series of cavitation filters and sand filtering to produce water that is low in suspended solids and bacteria. Chlorine is injected or created with an SWG at the final output stage and is typically designed to be very low level, around 0.5ppm. This will result in pool water that has a nominal hypochlorous acid concentration of around 200ppb or so which is quite high but not very irritating. Given the low levels of FC, hydraulic efficiency and good circulation of the water volume is critical.
I would simply stay away from the Dryden ACO stuff and order CYA online through Amazon or Walmart or wherever you can get it delivered.