No, I don't think these will do a kill-off this way.
My thoughts are that in making the body less of a nice house for the parasites, they will slowly die off. Take my word of it, he would not go for a full kill off thing - you'd NEVER hear the end of the complaining.
So far I've managed to cure him of his yeast problem. :> That took me 2.5 years. I figure this step is gonna take about as long.