No. This is an absurd folktale that has spelled the doom of thousands of these superb beasts. The horn of the rhinoceros is an agglutinated mass of hairs that sometimes falls apart when left too long in the water or mud. But nothing will persuade many Oriental people that they will not be cured of many ills by drinking it in solutions, swallowing it powdered, or even holding it in their hand for a prescribed number of hours.
Rhino's horn sells for great amounts though the Far East and poachers have no qualms about butchering the great beast.