Mikey0 are you talking about the liquid ammo lock or the amo chips. If you are talking about the liquid ammo lock, yes it works. Read teh directions on it and follow them. The thing with using this is it transforms tha ammonia out of the toxic form ( or gaseous state) into a non toxic form. I think you have to use it something like every 2 days, be sure and read how much ammo lock to use to neutralize how many ppms of ammonia, if you have any questions on this just let us know.
Your liquid test kit will still read off the charts for ammonia because these test kits read the total ammonia in the water. If you want to see if there is any toxic ammonia in your water after using the ammo lock you will need to purchase an ammo alert (they cost about 7 dollars and you can get them either offline or at your pet store, seachems ammo alert). You leave the ammo alert in your tank all the time, if you go this route and get an ammo alert it will remove the need for testing ammonia with a liquid test kit unless you just want to double check to make sure its working. The bottle of ammo lock says that your biological filter will remove the locked out ammonia over time, this takes a while. Anyways, I have used it, it worked for me, this is not a replacement for water changes, and you will still have to worry about nitrite spikes.
I thik OrionGirl is talking about ammo chips, if this is what you are talking about, follow what she said.Happy Fishkeeping