When I was in college, my landlord would just walk into the house uninvited without even knocking.

Quote from @Matthew Becker: The knock down cabinet that are made of 1/2 plywood shaker style are pretty good deal at home depot. 

Door Knocking for 3 months.

I hear so many things from door knocking to contacting your circle of influence but lets be realistic there is tons and tons of tools that make outreach way more effective.What would be a good way to market to get 5 listings this month?

Networking, local meetups, door knocking, mailers, wholesalers, online forums specific to your area of interest.  

PS before the hedge funds jumped in about 2011 to 2012 I was an activce courthouse buyer in Henry county and a few of the counties on the north side of Atl metro so been to many of the  auctions having them all on one day is a cluster .. you have multiple criers crying sales simultainously it can be hard to follow but you can also squeeze out one that folks missed.. we did quite well until the hedge funds knocked us little guys out of the area..

You've signed up for one PIA if the owner is still in the house.One way to tippie toe into this is to hook up with short sale agents and start working with them offering to door knock the NOD folks. 

That way, you might preserve some of your monthly profit while still knocking out that line of credit.

If you are nearby, if you have ever been a pizza delivery person, maybe deliver a pizza to the wrong house that may or may not be the one being foreclosed on so atleast you can see inside a small portion. we used to just go knock on the door some folks would actually let you look around.

Terrible idea, but knock yourself out.