No, snails will seal off inside their shells and wait you out. Also, pond snails seem to thrive in nitrates.
I did tear it down before but i made the mistake of trying to reuse some of my plants. I thought I had thoroughly pick through them and even did a mild bleach dip but i failed. Plants are hard to get here. The pet shops only stock the typical stuff.Empty the tank, use a fresh substrate, and wash everything else. Snails thrive on decaying organic matter and algae - remove what causes them to thrive/flourish.