Say you normally might be able to offer your house for $205K on a lease option. The other party pays $1,200 a month, and $200 of it goes to equity. Maybe you can offer it for $220K with a $1,250 monthly lease payment... but 100 percent goes to equity if they execute the option to buy!
This is a unique offer. At the end of one year, if they execute, they have to come up with $205,000 - about what you owe. If they don't execute, at least you've pulled in another $15K, reducing your negative cash flow.
Not ideal... but keep in mind that you're trying to make the best of a bad situation.