Do the souls of Protestants go to purgatory?

The Catholic Answers

All souls, whether of Protestants or of Catholics, or of any other religion, will go to purgatory if they are not good enough for heaven at the moment of death, nor bad enough for hell. Non-Catholics may deny purgatory, but that makes no difference to purgatory.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty