Hi xpistalpetex,
The topsoil I got was from Home Depot. I wrote a whole article on the mineralizing process
here.
I've included a list of materials in the article with a link to a picture of the exact topsoil that I used.
There's no need to boil the soil. The mineralizing process should only take 2-3 weeks now that the sun is nice and warm again and that will take care of the ammonia in a much more usable fashion.