I've been working with liquid latex for armour and large head appliances and yeah, the ammonia smell is pretty bad- can be dangerous too if there is not enough ventilation. Cosmetic grade latex is supposed to have low ammonia or no ammonia though.
It's an easy step to do at home though to reduce the ammonia smell if you want:
I used the same latex I cast from to stipple the edges on my head piece but it had been stored in a small container for so long with a little pocket of air that the smell had almost gone by then too.
And a nice summary of the different kinds of latex
And thanks for the review