It's kinda like they say...Real estate is a get rich scheme...but it's not a get rich quick scheme. (I'm "they")
BRRRR method is the best way to recycle the same money if you have no additional (or not a lot) of replenishing income from a day job. The ISSUE with BRRRR is that even in the best markets it dramatically reduces cash flow.
Here is my portfolio. It's no secret Detroit is the best market in the country for cash flow (That's fact, not bias), however, you will see in my portfolio that on my BRRRRs my ROI is great but my cash flow is very low. I've put most (rarely ever all) of my capital back into my pocket but that comes at the price of a higher mortgaged amount, and right now an 8% interest rate...sometimes really wiping out most cash flow.
The BRRRR method for cash flow can take years to decades to mature back into a cash flow giant.
Note: it's still the highest ROI method of investing...because if you only have $5k-$10k of your own money in a deal, it doesn't really matter if it's only cash flowing under $100 a month. But you have to REPEAT, ALOT.
Take a look at my highest cash flow property, 12 mile. Why is it my highest per door? Pretty much soley because it was my first. A solid deal in a great area bought in 2019 and rode the COVIC explosion up to $1700 a month in rent. That deal looked very "average" on paper in 2019. I have a decent amount of equity in this property at this point. I don't need the cash, so I'm just waiting on lower interest rates...knowing that when i do refinance it's going to kill my cash flow just like it does on all BRRRRs.
I think my encouragement, is to allow yourself to be patient. Getting rich quick, could make you do something that is closer to gambling than investing.
Instead, trust how good of an investment real estate is, pick a solid market that cash flows with solid ROI, invest your money, pull your equity out if you want, and just let 1. Cash flow 2. Appreciation 3. Loan pay down and 4. tax benefits do it's thing.
After being pretty theoretical, here are some direct answers:
Here is a thougth on the HELOC....now i haven't thought through this a ton...but the HELOC is already like a mortgage, hopefully at a decent interest rate....you could buy 2, $125k houses cash (not really cash, but with the heloc money and no 2nd mortgage) it will cash flow a lot, plenty to pay the HELOC and still cash flow.
The $100k in cash you could finance 3, $100k houses each cash flowing like $250 a month or so...so there's another $500.
So in total you would buy 5, single family homes around $100k-$125k each with a couple hundred dollars a door cash flow. Maybe you were hoping for 10s of thousand of dollars a month cash flow...but if that was out there..I'd already have my money in it.
Best of luck!