There wasn't a thick layer of ash to begin with, but the tops were chalky-looking. I used a tea kettle to do this, by the way...just held a bar up to the hot steam, moving back and forth. The steam melted the top, making it "gooey"...that is when I stopped because I didn't want to ruin the bars.
Did it work? Not 100%. I can still see some ash...not as much, but it's still there. The appearance, however, is much better...the tops of the bars have a nice sheen to them. I'm going to try the steam method again...on bars that have a thicker layer of ash, and will see how much they improve.
chamomile tea...with some honey
The good thing about using a tea kettle for this, is that when you're done, you can make yourself a cup of tea!