Why is dried, melting ice used in the experiment to find the specific latent heat of fusion of ice?

I think you mean something like an ice cube. Is this correct??

You need to use perfectly dry ice because you do not want to falsify your results by heating up the water that's on the ice.

Depending on the size of the ice cube, this could be a small error or a large one. In any event you could improve your results by refining all the possibilities of error.

Dried ice will cool the water to freezing since water freezes at a higher temp than dried ice. The dried ice will absorb the heat in the water to the point the water freezes. Some of the dry ice will melt but what melts will vanish as gas.

Water has a particular heat temperature of a million.00. the quantity of warmth required to enhance the temperature of a million pound of water a million degree F is a BTU (British Thermal Unit). It takes a pound of water to make a pound of ice (or steam). The latent (hidden) warmth is the quantity of warmth eradicated from water at 32 F to get ice at 32 F.