Not to make waves . . . but please be careful with the Oxyclean, as too much of it CAN harm fabric! Voice of experience, here!
You might also try washing it, with a mild shampoo, in cool water. As for the wedding dress, try "washing" a spot, with a baby wipe/wet wipe (a plain one, with NO aloe or other moisturizer). Depending upon the fabric, some wedding dresses can even be gently washed (cold water, mild detergent, air dried)! Since you'll be taking it apart, you can then repress the fabric, with a barely warm iron.