This is correct according to Catholic doctrine also.
Everyone undergoing purgation (purification) is in a state of grace--- destined for heaven. And they know it. Therefore Purgatory is a state of hope.
As a RCIA --- adult converts' ed --- teacher in my parish, I always minimize using the word "place" in relation to Purgatory, simply because it implies that it's "geographical." ("Gee, do you suppose it's a couple miles down there, under the crustal plates?")
Purgatory is simply a state required for most good people, to become detached from their sins and cleansed of the temporal "stains" of sin. I like the idea of the Bride getting her gown bleached, de-spotted and ironed --- of course that's a Biblical image.
It's as if you've been invited to the wedding feast and you were just in the midst of mucking out the hogs' pen. You'd BEG for the opportunity to get thoroughly washed before going in to the feast.
I do believe you also do your purgation here on earth as well.