I am about to switch to Amsoil ATF in my 2007 Civic LX. A drain and fill for my Civic takes 2.5 quarts, with a total fill of 7.3 quarts. It will take 3X drain and fill to replace almost all of the Honda Z1 in my vehicle accordingly.
I believe that your Accord takes ~4 quarts per drain and fill. Just like my car, it should take 3X drain and fill to replace the ATF in your Accord. You will need about 12 quarts of ATF if you plan to go this route. I recommend buying three one gallon containers of Amsoil ATF. If you are a PC it will cost ~$100 total to do this. Twelve quarts of Z1 will cost about $60, so you are looking at an extra $40 to use Amsoil instead.
