What do you clean your hamster with?

Hamsters cannot be cleaned. They should NEVER be put under water unless it is a emergency (ex. They walk into and acidic fluid). You can provide then with a dust/sand bath. This will give them a fluffier coat that smells good.
Syrian hamsters don't usually like dust baths, so it is better to get it for a dwarf hamster. There is a wide variety of hamster dust bath dust and Chinchilla Sand that can be used.