Rejuvenating Polly Pocket Dresses

My granddaughters have several Polly Pocket princess dolls with extra dresses and skirts. I keep them in a clear plastic shoe box. The skirts got sort of flattened, so they wouldn't hold the dolls up. To fix this, I used the medicine cups that come on bottles of over the counter meds (like cough syrup & liquid pain meds). I put one, inverted, under the skirts & dresses that are not on the dolls. I found I can put several skirts over each other, with the bottom one over the cup. It takes a while, but the skirts regain their shape & support the dolls again. I have also cut the bottom out of some cups & slid them (also inverted) under skirts while they are on the dolls. I think, if you were in a hurry to get the skirts back in shape, you could use a hairdryer or other heat source to speed up the process.