Is a pronouncement of Khul' (repudiation for compensation) valid when made by a third party without the wife's permission?

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The pronouncement of Khul' by a non-relative (stranger) to the husband, such as the third party saying, 'Divorce your wife for a thousand upon me,' is valid. This is the position held by the majority of scholars. The basis for this ruling is that the third party is offering money to extinguish a right belonging to someone else, which is permissible, similar to saying, 'Free your slave, and the price is upon me.' Furthermore, if a person says, 'Throw your goods into the sea, and the price is upon me,' this is valid and binding, even though it extinguishes no right for anyone, making the case of Khul' (which extinguishes a right) even more valid. Finally, the right being waived (the wife's right to the deferred Mahr) can be waived by someone other than her in exchange for compensation, just as a debt can be settled by another party.