It's nothing a little (something) can't[won't] fix.
I saw this kind of sentences a lot recently but couldn't figure out how to understand those. At first thought, they seem to have meanings such as "(something)" is not gonna help at all because it's too naive, crude or improper way to do that. Am I right? Then again, if my interpretation was correct, wouldn't they violate Double Negation rule? I mean, why don't you use like "It's something a little soap and water can't fix" or "It's nothing a little soap and water can fix"?