In a large bowl, combine the coconut and sweetened condensed milk. Stir with a wooden spoon or rubber spatula until evenly mixed.
Using tablespoons or a small cookie scoop, measure coconut mixture into balls of approximately 2 tablespoons each. Using your hands, gently roll and press each into a firm, smooth ball. (The mixture will be sticky; it helps to run your hands under cool water periodically while shaping the balls. If you're still having trouble, let the coconut mixture sit for 5-10 minutes at room temperature, then try again.)
Arrange balls on a baking sheet lined with parchment paper or silicone mats, being sure they do not touch. When finished shaping, place the entire baking sheet in the freezer for 30-60 minutes.
Just before removing the baking sheet from the freezer, melt chocolate wafers in a bowl according to package instructions, and lay a long sheet of parchment or wax paper out on the counter.
Remove coconut balls from the freezer, and working one at a time, dip each into the melted chocolate. Roll to coat completely, then lift gently with a fork. Hold for a moment to allow excess chocolate to drip back into the bowl, then transfer to the parchment paper to set. Sprinkle immediately with additional coconut flakes or sprinkles, if desired.
Truffles will set in about 30 minutes at room temperature, and then can be stacked for easy storage. Keep in the fridge, and serve cold or at room temperature.