dear bombadil,
your sculptures sound as if they never dried and are now fermenting or molding. it's clear you've got too much goop in your mix. got to use less of the gloppy stuff. You might try squeezing out the moisture before applying to sculpture. orm and previous advice giver said, using the strip and squeegee method.
If you want to try saving your smelly ones, try putting them in the oven
(I hope they'll fit) at a verrrry low temp for a little while. this might dry them out a bit. If your kitchen starts smelling like baking bread, it's past time to take them out! Good luck,
The River's Daughter