Then purgatory is a mighty full place right now.
Actually, purgatory doesn't make very much sense either. If you believe in salvation by faith alone then a person cannot be saved and still be punished. It does not matter how sinful they were it is their faith which causes them to be saved. Purgatory implies that God punishes people who have not atoned for specific sins even though they are saved. This implies that it is their own action of making pennace for sins which causes them to be forgiven rather than Jesus' blood on the cross.
Here is a link to a discussion of purgatory.
Incidentally the muslim position is that people who are dead experience the life of the grave where they are sleeping but are visited by angels who give them nightly visions of the heaven or hell which awaits them. Then everyone is raised up and given a new body so that they can be gathered on the plain of assembly for the last judgement.