There are two ways to properly sanitize dishware washed manually.
Water must be at least 180°F (82°C) to sanitize dishware. To raise water to that temperature you need a booster heater or an electrical heating element that can be immersed directly in the water. Since employees cannot remove items from 180-degree water with their hands they must use tongs or other devices.
It is frequently more practical to use a chemical sanitizing agent to sanitize dishes. If chemicals are used, the water does not need to be excessively hot. Use proper chemical sanitizing agents in the correct amount. Determine the quantities to use, and provide appropriate training and measuring utensils to employees.