The only other way sneasel can learn Icicle Crash is by learning it through an egg move. I won't go into how to to that here, but if you want to know how to get an egg move on a Pokemon here is Bulbapedia's page on egg moves.
In order to breed a sneasel, you can either breed a sneasel/weavile with a ditto, another sneasel/weavile or a male Pokemon of the same egg group (if the female isn't sneasel/weavile the Pokemon you hatch won't be a sneasel) since both sneasel and weavile belong to the field egg group here is a list of Pokemon in the field group that sneasel/weavile breed with.
Hope I helped!
