It makes more sense, to me at least, for the individual oath-taker to confirm his fidelity to his oath by invoking a curse on his own head if he breaks it than to curse anyone in general who breaks the oath. The oath itself is of course in the first person singular, and I think it follows that the confirmatory curse is, too.
On the Mysteries 31:
οἵ τινες ὅρκους μεγάλους ὀμόσαντες οἴσετε τὴν ψῆφον περὶ ἐμοῦ, καὶ ἀρασάμενοι τὰς μεγίστας ἀρὰς ὑμῖν τε αὐτοῖς καὶ παισὶ τοῖς ὑμετέροις αὐτῶν, ἦ μὴν ψηφιεῖσθαι περὶ ἐμοῦ τὰ δίκαια,
This is a different oath (the Heliastic Oath), but the formula seems to be a self-curse that each oath-taker invokes individually. (I recognize it could be read differently, but I think the most natural reading is that each oath-taker lays the curse on himself and his own family individually.)
Also sec. 126:
λαβόμενος τοῦ βωμοῦ ὤμοσεν ἦ μὴν μὴ εἶναί οἱ1 υἱὸν ἄλλον μηδὲ γενέσθαι πώποτε, εἰ μὴ Ἱππόνικον ἐκ τῆς Γλαύκωνος θυγατρός: ἢ ἐξώλη εἶναι καὶ αὐτὸν καὶ τὴν οἰκίαν, ὥσπερ ἔσται.
Not a perfectly clear example, since there is only one oath-taker, but it seems to reflect the same formulaic language.
See also Lycurgus 1.79:
καὶ μήν, ὦ ἄνδρες, καὶ τοῦθ᾽ ὑμᾶς δεῖ μαθεῖν, ὅτι τὸ συνέχον τὴν δημοκρατίαν ὅρκος ἐστί. τρία γάρ ἐστιν ἐξ ὧν ἡ πολιτεία συνέστηκεν, ὁ ἄρχων, ὁ δικαστής, ὁ ἰδιώτης. τούτων τοίνυν ἕκαστος ταύτην πίστιν δίδωσιν, εἰκότως: τοὺς μὲν γὰρ ἀνθρώπους πολλοὶ ἤδη ἐξαπατήσαντες καὶ διαλαθόντες οὐ μόνον τῶν παρόντων κινδύνων ἀπελύθησαν, ἀλλὰ καὶ τὸν ἄλλον χρόνον ἀθῷοι τῶν ἀδικημάτων τούτων εἰσί: τοὺς δὲ θεοὺς οὔτ᾽ ἂν ἐπιορκήσας τις λάθοι οὔτ᾽ ἂν ἐκφύγοι τὴν ἀπ᾽ αὐτῶν τιμωρίαν, ἀλλ᾽ εἰ μὴ αὐτός, οἱ παῖδές γε καὶ τὸ γένος ἅπαν τὸ τοῦ ἐπιορκήσαντος μεγάλοις ἀτυχήμασι περιπίπτει.
I think there are other examples of such oaths, where a self-curse is invoked on himself by the oath-taker individually.
εἰ οὖν γνώσονται ὑμᾶς ἀποδεχομένους τὰς κατηγορίας τῶν πρότερον γεγενημένων, – if they, not you, learn that you