If you discover that you can't get a candle out of a votive holder, put it into the freezer until it's cold. Then the candle should pop right out. If small candlesticks have wax left on them that you can't remove easily, put them into the freezer too. When the wax is solid, it can be flicked off.
Have you cleaned it, in addition to the regular dish cleaning? Dishwashers need a good cleaning too. The cleaner it is, the better it will work. To remove stains, sprinkle instant powdered orange or lemon breakfast drink on them. Let stand for about an hour. Wipe off.