Lutherans are rather adamant that it is Christ alone who hold us, regardless of the machinations of man. Even today, when Catholics no longer have the practice of purchasing indulgences, we still maintain this - there are many lonely people who the world has forgotten, and we would not compound their suffering in a purgatory that they would linger in longer if no one is praying for them.
That said, Lutherans should have no trouble with the kindness that Catholic show in the prayers that effect souls leaving purgatory.
12] First, purgatory. Here they carried their trade into purgatory by masses for souls, and vigils, and weekly, monthly, and yearly celebrations of obsequies, and finally by the Common Week and All Souls’ Day, by soul-baths so that the Mass is used almost alone for the dead, although Christ has instituted the Sacrament alone for the living. Therefore purgatory, and every solemnity, rite, and commerce connected with it, is to be regarded as nothing but a specter of the devil. For it conflicts with the chief article [which teaches] that only Christ, and not the works of men, are to help [set free] souls. Not to mention the fact that nothing has been [divinely] commanded or enjoined upon us concerning the dead. Therefore all this may be safely omitted, even if it were no error and idolatry