"Thank you for the quote."
So how do you think that quote bears upon the articles presupposition that there are two punishments for sin (eternal & temporal) we must deal with before we are fully clean?
If full cleansing & forginess required indulgences (or the "punishment" indulgences supposedly pay for) then how could the verse claim that we can obtain full forgivness and full purification though simply confessing our sins?
I think you're constructing a contradiction where none exists. It says "if we confess, then we will be fully purified," but it doesn't tell you how that purification will take place or what can make it happen more expeditiously.
To put it in concrete terms, anyone who dies having confessed all mortal sins goes to heaven. If necessary, they are cleansed in purgatory (if not before they die). Therefore, anyone who confesses is cleansed. No indulgences are required, but that's not the same thing as saying that they aren't helpful.
The cited verse is not inconsistent with Catholic doctrine at all.
Yawn. Forgiveness does not require indulgencies. Read the damn article.