We built out our own portal and accounting database for that functionality because we were not finding good software that could handle a higher volume of receipts AND tie it in with the rental property accounting. 

Where can I find proper leads or wholesalers?

When using this structure for investments, the key is to complete IRS Form W9 properly.

The answer sort of varies on a few factors like are you self-managing, have you had a proper conversation with them over the phone, etc... 

It was very complicated and cumbersome to set up properly and difficult to use.

I like the functionality a lot but it seems that once a month there's a new bug to contend with that's eating into my time.

I am now looking for advice on how to structure my bank accounts to properly separate my personal expenses from any expenses surrounding my house hack.

When done properly, they have a high probability of resolving the problem.

It can be drained every use (as long as you have an area to drain it properly to so this would be the only hold back) so no chemicals needed or reliance on a Hot Tub maintenance person2.

I never used it in the way you are describing but I can attest to its functionality.