Make your salt solution by the addition of salt to the water in not more than 1:3 proportion. At higher concentrations, the solution will saturate and will crystallize. Make your sugar solution by adding sugar to the water in not more than 2:3 proportion. If you add too much sugar, the solution will crystallize and can not be poured. Heating the water dissolves the salt and sugar will accelerate the melting process, because heating the water raises the point of saturation, which means that you can add more solute – salt or sugar – to each solution, and the hot water temperature increases quickly when added to the ice.
Use hand protection, such as gloves, when handling ice to avoid injury.