I rather stupidly put 70 quid's worth of silk skirt through the washing machine. It is, to say the least, a shadow of it's previous silky black self. I mean, the dye hasn't washed out completely or anything, but it now has a grey sheen to it that it didn't have before but which makes it look old. I know silk is tricksy stuff. Any tips on restoring it to its former glory?