Place the pretzels, one at a time, into the boiling water for 30 seconds. Remove them from the water using a slotted spoon. Return to prepared cookie sheet, brush the top of each pretzel with the beaten egg yolk and water mixture and sprinkle with the pretzel salt. Bake until dark golden brown in color, approximately 12 to 14 minutes. Transfer to a cooling rack for at least 5 minutes before serving.