Then do a thorough research on tenant applicants (note: leaving this to a PM may be hazardous to your financial health) and choose the one that is most “stable” with the best potential for long term tenancy.This advice is contrary to maximization of rental income, but IMO will reduce expenses of tenant turnover, property damage, property management fees so much that the difference in bottom line income will be quite small.  

In neighborhoods that won't attract high credit score tenants, I've found that a stable job history with a MINIMUM of 1 year at current or previous job to be the best indicator of a great tenant. 

Assuming you go the HELOC route, another option to reduce your costs assuming you have decent credit is to look at credit card balance transfer promotions.Back in 2003-2004 I had HELOCs on my investment properties and interest rates were increasing.

Is the line of credit different from refinancing the home that is free and clear? 

No social or credit pull needed upfront. 

And when you said the management company takes a 550 credit score , all I see in your future are evictions .   

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

Some parcels are actually worth as much or more after the credits are clipped as before. 

We're considering doing something like Dave's cookies via Amazon but that's only semi-fresh baked and subject to shipping damage. 

Otherwise, talk to your bank or credit union.