Heat oven to 200 degrees F. Line 2 large baking sheets with parchment or wax paper. In large bowl, combine egg whites, sugar, and salt. Place bowl over a pot of gently simmering water, and whisk constantly until sugar dissolves and mixture feels warm to the touch, about 5 minutes.
Remove bowl from water bath. With mixer on high speed, beat egg-white mixture until stiff peaks form, about 8 minutes. Spoon meringue into a large bag fitted with a star tip. Pipe 1-1/2-inch-size kisses onto baking sheets lined with paper. Bake 1 hour. Turn off oven, but leave in meringues until completely cool, about 1 hour.
Place melting wafers in 3 separate bowls, with 1/2 teaspoon vegetable shortening in each. Microwave 30 seconds, stir, and microwave 30 seconds more, until melted. Line counter with wax paper. Dip cooled kisses into melted wafers, place on parchment or wax paper, and cool completely.