Okay, you’ve sealed everything, dried everything, and put up barriers. But one brave soldier always makes it through. What then? You must not scream. You must act.
Keep a roll of paper towels and a spray bottle of white vinegar handy. Vinegar dissolves their slime and kills them instantly. A quick spritz, and they turn into a sad little puddle. Boom. Mic drop. Just vacuum up the remains quickly before it stains your grout.
If you’re too squeamish for the kill, get a plastic container and a dustpan. Scoop the slug up and throw it outside into the bushes. Let it live to fight another day? No. Let a bird eat it. That’s called wildlife management.