Unfortunately, the cure may be successful but you risk killing the patient. Rhino Glue can be dissolved with nail polish remover (acetone). But using acetone or any other solvent on your leather dashboard isn't risk-free. I'd use a cotton swab dipped in nail polish remover to carefully wipe that spot of Rhino Glue, let it sit and become absorbed before repeating the process. Be patient and don't overdo it. You want the acetone to soften the Rhino Glue while keeping it from soaking into the leather. As the Rhino Glue softens, carefully remove as much as possible with your fingernail or a plastic spoon, then swab it again and repeat.

From the manufacturer, Rhino Glue:
https://www.rhinoglue.com/first-aid#...0off%20easily.

Using acetone to clean leather:
https://www.hunker.com/12001225/how-...r-with-acetone

Good luck!