Ohio Rev. Code § 4719.09: Waiver of rights.

(A) No telephone solicitor or salesperson shall cause or attempt to cause a purchaser to waive a right granted under section 4719.07 or 4719.15 of the Revised Code.

(B) Any waiver by a purchaser of a right granted under section 4719.07 or 4719.15 of the Revised Code is contrary to the fundamental public policy of this state and is void and unenforceable.