Rusty,
I read the Anastasis blog quite often, as I am also interested in ecumenism with the Eastern churches. It's the blog of the Holy Resurrection Monastery a Byzantine Catholic monastery in California. Here's their about page. Anyway, I just wanted to pass along this post, which I found interesting:
http://hrm.ductape.net/blog/index.ph...Purgatory.html
Trent Session 14, 9 states "It [the council] teaches furthermore that the liberality of the divine munificence is so great that we are able through Jesus Christ to make satisfaction to God the Father not only by punishments voluntarily undertaken by ourselves to atone for sins, or by those imposed by the judgment of the priest according to the measure of our offense, but also, and this is the greatest proof of love, by the temporal afflictions imposed by God and borne patiently by us. "
It is clear that the punishments are imposed by:
The priest
Ourselves
God
These punishments are inflicted external punishments, and not the "existential consequences of sin", as Fr. Kimel says.