What test can be performed to confirm an experimental product is an ionic compound?

Ionic compounds ionize in aqueous solution but some molecular compounds ionize in aqueous solution as well, such as HCl. Also not all ionic compounds are soluble in water.
We can heat up the product to its melting point and if it has a very high melting point then that could tell you that it is an ionic compound. We can therefore conduct an electric current through its molten state, and if it conducts electricity then it is an ionic compound. Basically, the big hit on the head will be if the compound conducts electricity in its molten state.

Just generally, dissolve it in water and see if it conducts electricity.

More specifically, if you have the ability to melt it, do so and see if it conducts electricity as a liquid.