The only battery desulfator that does 6V is "Wizbang" you can google it. I have a couple of these and all I can tell you that small items like this can only correct minor sulfation maybe up to Cat2, that's it, and can keep the battery "clean" inside. I don't recommend it if you have a heavily sulphated battery. For Cat3 sulfated batteries you should make your own. I have unit called Mini CIP (Charged Inductive Pulse). Even with that a heavy sulfated battery takes up to a week to clear out (from everything white inside until there is nothing left). The next one down was the "BLS" it took about a month. Sorry I don't have the Pulestech to compare. Desulfating does work, but it really depends on how bad the battery is plus what you use to desulfate it with. Infinitum and Wizbang were last as they couldn't do anything with cat3 sulfation, even not after 8 months! I don't want to say that these 2 are useless, I have mounted one on my sports car with a C-Tek charger), to keep the battery from sulfating another one on my tractor, next one on the generator, etc., Works A1.
Others hook an electric fence energizer up to the battery and let er go.