I would look at private money lenders who can consider giving your a line of credit based on a multiple of the cash you have. 

Depending on the market your looking to work in.one way I find is to simply call one of the major title companies and ask to talk to an escrow officer and then ask them what companies does he/she see closing private loans in their market..

I know people who do STR in their house, but it's as private as possible.

Does each room have its own private bathroom or is there a shared hall bathroom? 

You may want to find a private lender, sell something, etc…The mortgage lates are going to keep you from any bank/mortgage products

Any lender, private or conventional, will have some hoops, maybe just not as many for private lenders...

After arrival they're disappointed to find it's not a private bedroom, which leads to disgruntled guests that search for way to get a refund and leave bad reviews.

Private lenders can't do it.

I have more than enough private investors willing to pour their money in and I realize that there are diminishing returns when considering time spent looking for deals or deal finders and the amount of deals I close.I'm a real believer of the Pareto law which states that 20% of effort leads to 80% of results.

If the group is a private group, it is treated like a private email I believe.