We lowered our price slightly and instantly demand increased.

Because cash can get spent instantly.

You all have clean and manage yourself to make any profit at all, and you'll get really tired of cleaning up after your friend for no money.Like John said just put it on VRBO and AIR and turn off the instant booking feature so everyone has to be approved by you before booking . .... 

But my worry is that offmarket might be the only way to find a property that is reasonably priced or to create instant equity.

You cashflow, pick up instant equity at the buy and force in equity.

We now own a highly desirable duplex with instant equity, cash flow, low money down, and a locked interest rate.

We now own a highly desirable duplex with instant equity, cash flow, and no money invested.

I instantly thought to myself that's strange I bet DJ contacted him and told him to write something positive.

This instant gratification era will learn. 

I know HELOCs can be a great way to get some instant liquidity, thats why I figured my only options would be fix & flips/BRRRR properties, but I wanted to hear from people like yourself and others here who are much more experienced than myself!