While I was watching the episode “It Isn't the Mane Thing About You”, I heard Pinkie Pie says to Rarity: “Great! Hey, is there something different about you? New hoof polish?” I looked up hoof polish on the web, and then found out that this is a real world product.

Hoof Care & Polish

Can you imagine a sleeping stallion that gets pranked by his friends who polishes his hooves with sparkly hoof polish?

Twinkle Glitter Products

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Heh.

Don't forget to braid his mane and tail while you are already at it.