True that!
Cycling is not about what happens to the water: that's replaceable. It's about what happens to the rock and sand and the bacterial population that lives way deep in the pores of the rock and sand. That's where your water gets purified and re-calciumed and all those good operations. You can keep a rock in a stream for a week, and crack it open and water will have penetrated only a little ways from the surface. Take a rock that's been in the stream for a long time, crack it open, and you will see a difference. So these bacterial doses are nice: we used to do that back in the day---in the 1980's, we'd use dry rock and crushed coral sand and get a couple of gallons of discard water from the lfs, pour it in, and wait 12 weeks for the dose to do its job, bringing in a lot of bacteria in that water. But it also might bring in ich and viruses and other badness, so we went over to just using fish-food with dry (but washed) aragonite sand (doesn't clump like CC) and conditioned rock that's been soaked in saltwater for weeks and weeks---and manage a 4 week cycle.
The bacteria-in-a-bottle are concentrated, yes, but they still need time to really colonize your tank. By adding ammonia, you're just feeding the bacteria, and DO UNDERSTAND that once that's done, you never add it again---it'll kill your fish. The idea is that it hypes the strain of bacteria that take care of ammonia if it should arise. But ammonia is NOT a desirable part of tank chemistry---I've run into one post that makes me think I should make that point: ammonia is not a fix for a tank problem. Keep a bottle of Prime or Amquel on hand, always, so that if you have a tank headed for trouble, that ammonia-absorber can save your bacon. Another thing you should think of is eliminating phosphate (algae fuel) that may come in with unconditioned sand and rock, or non-ro/di water. If you're conditioning your own rock, you might think about starting a GFO reactor running on the tub.
Anyway, that's the accumulated wisdom we've got to offer you: the bacteria speed it, but cannot overcome the physical problem of not-enough-time-to-grow, and going very slowly with additions of life beyond invertebrates is the best way to go.
