Vintage Tacky Stretchoid Warriors (Giraya Ninja); a sticky problem
 

Do someone remember these? they were a japanese line of elastic figures, sold in the US as "Tacky Stretchoid Warriors" by Bandai. I had one as a kid and I loved them.

Question is, now I have 3 of them in my collection, but one of them has degraded, presumably due to heat, and has become very tacky and lost it's composure, so much that a bit of his hand has stuck to the box :( . Do you know some remedy to restore him to a better condition? I thought about baby oil, but not sure and I don't want to make matters even worse.

And, how do you think it's best to keep these elastic figures? in the box surely not as they get too hot, do I keep in a zip bag or I display them in the shelf in open air?

All ideas are welcome.