I can't tell you how you can clear this specific figure, if there is a way, but I can tell you that when it gets to the point that there is discoloration on the figure itself, it will take more than soap and water to remove it. There are ways I've seen of cleaning yellowed plastics, but I don't know if the same applies to vinyl.
There is always the chance that you're wrong that it's supposed to be clear and not smoky yellow. Also bear in mind that over time, clear vinyl has a tendency to yellow and it doesn't have to happen from smoke damage specifically.


