Grease a cookie sheet with the vegetable oil.Combine the caramels and the water in a saucepan and melt over low heat, stirring frequently, or in a covered dish in a microwave at full power, for 1 1/2 minutes. Dip the pretzel nuggets, a few at a time, in the caramel and remove with a fork to the greased cookie sheet.Refrigertate until caramel is firm. Melt the 3 ounces of the chocolate.Remove from heat.While the chocolate is still hot, mix the remaining 1 ounce of chocolate into the melted chocolate, in 2 additions, stirring until each addition is completely melted before adding the next. Lift the caramels from the sheet and dip, one at a time, into the chocolate.Coat completely and lift with a small fork.Shake off excess chocolate by rapping the fork on the edge of the bowl lightly.Remove any drips from the bottom by running the fork across the edge of the bowl. Slide the candy onto a cookie sheet lined with parchment paper or wax paper.Allow to cool until solid.Let chocolate set at room temperature or in the refrigerator.Makes 3 dozen chocolates, about 18 servings..