I've never seen a kuhli eat snails but my orange finned loach [ botia]did , they don't actually crack the shells , they find snails ,small ones . They turn them over and go in the shell opening and eat the snail [meat].I guess a kuhli could do this also . kuhlis and botias are very different loaches , I keep both , it is best to feed them at night if you don't think they are getting food , they are nocturnal. In my case it was malayan snails also nocturnal , very hard to crack , empty shells all over the tank . .