I have very fine, flat hair that no amount of volumising shampoo, conditioner, spray or mousse makes the slightest bit of difference to. I can get the tiniest bit of volume by using mousse and root lifting type sprays and drying my hair upside down, but within 5 minutes it's completely limp and flat again. I keep on hearing about how wonderful volumising root powders are. Has anyone tried them? Do they work or are they just another waste of money?