Snails are adorable. Baby snails are the some of the cutest things I've ever seen.
But back to topic
This is an interesting theoretical idea, and PadmaVonSamba answered it beautifully, as usual.
While they're snailing it up, what can you do to help, as far as your capacity allows?
Watch where you walk, especially when the ground is wet, so you don't squish any. That's already very useful to a snail
Second, don't stop there but actively generate benevolence and concern for any being you become aware of, even the small and slimy ones.
So many people just ignore beings. Many more blindly respond to aversion and splat bugs (or people) they don't like.
How rare and wonderful to be aware of your own potential for ignorance and aversion and turn them to concern, not killing beings carelessly underfoot, adopting a loving and engaged attitude instead!