I've seen this done in the play of the day points contest and it seems to have some success. What you do is bet on the dog and the favorite PL. One is guaranteed to lose obv, but if you hit either the dog ML or the fave PL you make profit.
I bet $5 on the following:
PIT (+175)
WAS PL (+150)
NYI (+125)
NYR PL (+210)
MTL (+140)
BUF PL (+180)
STL (+160)
DET PL (+160)
LA (+100)
COL PL (+220)
ANA (+170)
VAN PL (+160)
As you can see one goal games for the favorite result in losses for both but if you hit one of two plays in each game you will make a profit. Let's see how this goes
I bet $5 on the following:
PIT (+175)
WAS PL (+150)
NYI (+125)
NYR PL (+210)
MTL (+140)
BUF PL (+180)
STL (+160)
DET PL (+160)
LA (+100)
COL PL (+220)
ANA (+170)
VAN PL (+160)
As you can see one goal games for the favorite result in losses for both but if you hit one of two plays in each game you will make a profit. Let's see how this goes

I am just gonna do this for a week and bet $5 on each outcome and see how I end up. I forgot about your thread and you doing this, good work you are on to something 
I will call it the Fjordo System
, see what that will turn up for you
if going double-dipping.