Well... I don't want to change this thread into a disagreement about a variety of fish... however, I would agree that a "group" of maybe 3 fish is desirable, but although the fish can get large, 12" or more, they grow quite slowly after an intitial surge in the first year. It's jhust that while "control" of the snails is desirable, they do perform a valuable service and shouldn't be entirely eliminated... th eLoaches will do that.
Hint: sometimes it's necessary to smash open the shell of one or two slime-makers so the Loach 'get's the idea' and discovers they are food!
By the way there are other, smaller varieties of the Loach, such as Zebra or Angelicus that only grow to a few inches in length when adults... just as good at enjoying a lunch of snails...