Any other alternatives?

This is just looking at alternative funding strategies after those have been completed, which should be in the coming month. 

Here's something I wrote this summer for BP blog about one of my client's experience earlier this year:https://www.biggerpockets.com/blog/loans-gone-wild-turning-a-loan-into-a-flipMost of the time, these defaults can be worked out prior to foreclosure but you are absolutely correct that when it gets to this "nuclear option" as my co-author calls it, it can be time consuming.

If I was buying a house to live in or buying an investment property from a real estate agent, I would simply apply for a mortgage, but is there an alternative for these off-market offers that I'm not looking at?

Alternatively, you could check out Facebook marketplace listings and see what room listings are actually going for.Expenses could be different than long-term also.

Going through the HELOC route probably sounds like the best thing considered, alternatively you could also potentially refinance - it depends on how much money you pull out and what you can handle monthly cost wise. 

Alternatively, you can do much better by house hacking a 4 plex and still get an FHA loan. 

But there are alternative investments as well such as private lending, notes, tax liens.

Or alternatively, the homeowner dismisses the BK after stopping the sale and the process starts over.

@Victoria S.In terms of opening SDIRA or solo 401k, I'd solo401k has more advantages, but you have to ensure you qualify to open one up.As for the benefits, it allows you to diversify your retirement portfolio out of Wall Street into alternative assets.