Do you mean a second home for yourself or as an investment.....?
Actually knocking on doors does work, knock on the door of properties with for sale signs posted, tell the seller you don't want to waste their time, yours or the agents and if they would consider financing, then go into your pitch.
Look for older landlords who would like to retire, they get rid of the headaches have an income a deferr taxes, good deal for a retiring landlord.
Go to foreclosures, some there may be flipping the purchase.
Look for rent-to own ads and make them your offer, don't fall for the rent-to-own scam stuff, make your pitch.
Look in the Recorder's Office for those who have carried notes, non bank lenders, like Jerry Jones, LLC, then check the records to see what properties they own, go look and contact them with your offer.
Go make friends with a nursing home administrator. New residents will often be selling their home and chances are good that the adminstrator will ultimately be getting the proceeds to pay for care. BTW, this is a strategy all to itself and can keep you busy if you understand the system.
Get with a note buyer who picks up non-performing loans, try to buy out the original borrower and assume the note.
Check the foreclosures and see if an individual or non-banking type is foreclosing, work out the note and buy from the owner, it's better than a foreclosure for both of them.
Just because Realtors don't "do" seller financed deals does not mean you can not make the offer and spell out the terms. Look for slow moving properties and those pulled off the MLS.
There ya go, get busy....good luck