What are you asking for when going to the shops?
If you go to a chemist then ask for ammoniun hydroxide solution.
But you could use ammonium chloride (that's even been put in cough medicines).
If you get normal household ammonia, then make sure it does not contain anything else other than ammonium hydroxide. Some may contain lather agents and perfumes.
My personal opinion of the standard fishless-cycle that is published on the web is it is not the answer.
It should be called the 'chemical bottle' cycling as it simply doesn't cycle a tank like magic; a 'fishless cycle' should be exactly that....but the ammonia dosing is not a 'fishless cycle'.
Pissing into a couple of tablespoons would probably be even much better. (you just write that in a diary

).
ian