My experience says you're not going to be able you use that keg, but I've never waited for hops to break down, however long that might take.
I'd purge a bit, set regulator at 10 psi and blast some co2 thru the liquid out tube. Let it sit for a day and try to pour from tap. If its still clogged, purge all gas, swap the liquid and gas posts and then lay the keg on the ground gas in side down. Hook beer connect to gas in post and 5+ ft of line to another keg's liquid out tube. When settled, turn regulator to 5 psi and connect to full keg. Then hook up the liquid lines and purge new keg, beer will start going over. Purge continuously until all beer is transferred, could take 5-10 min.
So you want the little gas in tube facing the ground with a liquid out post on that side of the keg. The gas line will connect to the diptube side.That'll keep the hops from transferring or clogging. I dry hop this way now and use it as a filter.