Why won't normal lending methods work for us?

I picked up the BRRRR method book and feeling confident in setting it all up (we did a similar process for our Airbnbs).  

I think what @Garrett Brown is getting at is using this in addition to other methods.

I do not have to much cash for a down payment but was thinking of doing a HELOC on one of the rentals to get more cash and go the BRRRR method.

I am sure there are people who did it, even on this forum I saw posts by multiple users who claimed that they were successful doing this method.

The BRRRR method (Buy, Rehab, Rent, Refinance, Repeat) could also be a great strategy to recycle your capital.To find deals, try direct mail campaigns targeting absentee owners or distressed properties, or go driving for dollars in neighborhoods with strong rental potential.

This method typically provides an accurate, data-driven view before deciding to move forward with a property.

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

They say that they focus on the BRRR method, they handle the rehab (usually 90 days) and manage the properties.

As a general contractor, i feel best suited for fix and flip or BRRR method investing.