Well, welcome back then, even if you're a filthy dubfag>I'm wondering why don't they just throw all the snails into salt water so they shrink and lose their shells? That or just wait for them all to fucking die, not like 20 years
Why is everyone missing it? Reread top left panel. Most slugs can't just shed their shell anymore, and there are some who basically integrated gemdust into their DNA so they'd need to halt their reproduction as well to retrieve all of gemdust. Whether now or later, they'd still need to genocide the slugs.