Removing Leaf Shine!

[InspirChid1712]

I rescued a Potinara from a local grocery store lately, and it has really been declining steadily. I am suspecting that they sprayed it with leaf shine in the floral department to make it more appealing, without knowing that this is very unhealthy for any plant! I have kept it well-watered because the mix dries out VERY rapidly, but it is still shriveling, as if unable to take in moisture from the air. Does anybody know how to remove the shine with some sort of soap or solution? I really want to save this plant, because it is still early enough that I think it will survive, plus, the flowers are a lovely solid yellow! Thanks!

PS- Pot. Free Spirit 'Miami Sun'... it doesn't get any more yellow than this! Indeed it is a delightful and cheerful plant! Supposedly vigorous and easy... if I could just get that shiny s*** off of the leaves!!!