When cycling a tank using the ammonia method it takes approximately a month to get to the stage where the tank will clear 2 ppm of ammonia in 12 hours continuously. This method helps the seahorses not be exposed to any unwanted pathogens that could be lurking in live rock. They aren't really more sensitive to water quality (ammonia, nitrites and nitrates) than other fish - but are more sensitive to pathogens in the water. This is one of the reasons that we keep the water temperature down - to discourage the growth of unwanted pathogens. As far as I know, Heath is using the ammonia method for cycling.
Also, when using this method you can add multiple livestock at once and not have to worry about the tank's ability to clear the ammonia.
When I cycled my tank for my dwarf seahorses I cycled it to clear 8ppm of ammonia every 12 hours and was able to put 100 seahorses in there at once. Never once had a hint of ammonia or nitrites in that system - a truly wonderful way to cycle and know for sure your system can handle the livestock you add.