Does this type of wagering eventually get crushed??

My local is giving me NHL dogs at the opposite ML of the favorite.  (Ex: Wash vs. Tor, Wash -160...I'm getting Tor at +160)  So I was looking for a way to bet with this slight advantage...here is the only remote "system" I came up with that seems to be high risk, but did well in December and wondering if anyone has tried anything like this before:

Place wagers on both teams: wager 1 unit on the ML underdog, also wager 1 unit on the PL favorite.  Only wager on games where favorite is -150 or higher. 

Seems too simple and I get crushed on games where the favorite only wins by 1, but I looked back at past scores and it went 49-9 in December with a lot of the big dogs actually winning outright to make it a nice month.  I'll do more homework before I actually do it but I wanted to see if anyone in the forum has experience or opinions on doing anything like this.  Again, the only reason I even looked into something like this is because I'm getting these dog lines at a slight advantage compared to all other books.

anytime you can beat the closing line by such a margin over time you should make a profit.

GMSI

i find this calculator useful when looking to arbitrage..you may want to look at playing one side with the local and one side with a book..anytime u have a positive expectancy.its free money !

https://www.freesportsarbitrage.com/calculator.php

I was planning on playing with 2 books, thanks

I'll post how its doing halfway point and at the end of the month...right now it's doing alright, but losers lose 2 units  

January record: 7-0  +4.67 units

tried it today. 2-0 +1.84 units

doesnt feel like it will work long term, but im using small enough units, and i trust your stats, so what the hell... im with ya!

a couple close calls, but 7-0 + 4.6 units nonetheless... i think id use a chase system if i ever really got into using this. still in the trial stage... still like it though... obviously... it is 7-0.