[metmom]

It doesn't say how they washed their robes white.

Then it can't be presumed to be purgatory.

Then again, there's this.

Revelation 7:14I said to him, "Sir, you know." And he said to me, "These are the ones coming out of the great tribulation. They have washed their robes and made them white in the blood of the Lamb."

[St_Thomas_Aquinas]

"Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come." --Jesus

The clear implication is that some sins can be forgiven after death.

Christ's Church teaches that these sins are "venial" sins, or those sins that do "not lead to death."

There is also the following passage from Maccabees that Luther excised from his Bible:

2 Maccabees 12:46

It is therefore a holy and wholesome thought to pray for the dead, that they may be loosed from sins.