What I've heard about red wigglers (but not sure if accurate) - they differ from native earth worms because they live closer to the soil surface and therefore can't survive our winters. The "salts" needs more definition and research as there's the potential for affecting your soil profile.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize that we can't eat money. Cree proverb
