Permutit or zeolite is the aluminosilicate of sodium. It is used to remove hardness of water. It converts insoluble salts of $\mathrm{Ca}^{2+}$ and $\mathrm{Mg}^{2+}$ into soluble zeolites. It exchange these ions with $\mathrm{Na}^{+}$and water becomes soft.
Thus exhausted permutit does not contain $\mathrm{Na}^{+}$ions.