Answer:
Purgatory is a place/process of purification before someone enters heaven, since nothing unclean shall enter heaven (Rev. 21:27). Everyone in purgatory will make it to heaven. You can't do anything to get out of purgatory - it is only because of Jesus Christ and His sacrifice that anyone is able to enter heaven. The holy souls in purgatory are not experiencing a different or additional cleansing, but only the final effects of the one cleansing in the blood of Christ.