I think you are asking about an unsecured loan type of thing.

There is no law, or other regulation regarding this....it's all in the language of the approval letter, and whether a full release and waiver was negotiated at the time, or simply a release of the lien in which case it is still an owed debt, only unsecured and could likely be satisfied for less than 10%..

This service offers to find me multiple lines of unsecured credit, at 0% APR for 12 months, through personal and business credit cards.

No, the debt is not wiped out, the security interest is, so the lender can go after payment but they are now unsecured.

Get A $10,000 Unsecured Credit Card.

They offer unsecured lines of credit based on credit score.  0% interest for 12-24 months with an up front fee.  

I doubt you will find any institution that will lend to you unsecured with subpar credit.

If you're an unsecured creditor, you're kinda screwed as you might only get 10% or your money, but since you're providing their housing, you're likely going to come out OK.

Or that the tenants start subletting every room in the house and the basement to drugies.Holding a property unleveraged (all cash) reduces your ROI significantly.

As a lender using cards is fine just make sure you have the funds seasoned (2+ billing cycles) in your account prior to engaging into a loan transaction because funds sourced from an unsecured source cannot be used as down payment or closing costs.