I don’t have any Alto’s in my collection but let’s tag @lavenderjunkie.
When I got my Kingston, it needed to be cleaned badly. I did get the tassels wet, and used 2 clear rubber bands (from the arsenal of kids hair products I’ve accumulated 😆) to place around them, towards the bottom. They didn’t leave any indentations. And they are still laying flat.I wrapped the tassels in paper towels and taped them to dry.