I don't have a beef with anyone who likes those options, but I really hate them.
For #1, I don't let anything just rot in the tank if I can help it...that's poor husbandry. I don't see why it should be The Way to start a tank. If I wanted to try it, I'd look up some infor on http://scholar.google.com on rotting shrimp in saltwater to see what else to expect aside from nitrifying bacteria. For #2, thanks to terrorists it's now impossible to find plain ammonia in a bottle, anywhere near civilization.....it's all laced with soap or detergent and fragrances nowadays. I wouldn't trust any ammonia from a consumer outlet.
So what? There are better options for me...and maybe you:
3) Taking your time and using dilution. (One fish's ammonia in a large tank = dillution.) It works well. It's not fishless – but it's not a problem either. Only about ten zillion tanks were cycled successfully like this over history. It also works 100% of the time, in saltwater or freshwater. You just add the smallest bio-load you can at the beginning and build it up slowly over time. And you don't have to start with a fish if you'd rather start with a crab or snail or....use your imagination.
4) Using a bacterial additive like Bio-spira and following the directions which at least several people do not find hard.
Why not just use dr. Tims ammonia which was made for this question mark and said of trying to Source some other ammonia from the store