you can do foam latex but not slush latex?????
well providing you molded correctly, you just pour your latex in. or brush it in.
with a dwell casting you fill up the mold and let it set for 10 min, then you turn it over and let it drip for 10, i like to then set it on a desk and stick a fan to it for 5-10 min then repeat all steps. i do this 3 times for my masks.
for a one part mold, i just brush in layers, putting a fan to each one.