I recently purchased a lightly used Sparkle Athletic Headsweats Tiara visor from Poshmark. Poshmark is an online marketplace where users can buy and sell new and used goods, mostly clothing.
I washed the visor in the dishwasher as usual. This time, I was surprised to see that the plastic tiara portion of the hat was totally stripped of its sparkly shine! The coating was completely washed off and appeared translucent. There was some expected color loss to the pink fabric part of the visor as well.
Of course, I forgot to take a before image of the hat before washing. This hat still sells new, and you can see how the tiara should be shiny silver on the product images here: Pink Tiara Sparkle Headsweats Visor (Silver Tiara). The below image shows what happened when this visor went through the dishwasher.