Largest Sustainable _Loss_ Rate?

[parappa]

I've been wondering about the most common question on the limit forums turned on its head. Let's say a player plays limit hold'em very badly (let's say Party .5/1 if it'll help). His VP$P is 100% and he calls to the river if he gets any piece of the board on the flop, otherwise he folds (or something).

My question is: What is the largest sustainable losing rate for this guy in bb/100? We hear numbers about 5bb/100 being near the top sustainable winning rate. How much is it possible to lose long-term? 10bb/100? 15? Less?

Just wondering if anyone had a range for this.