A percentage of the rent is taken off the purchase price and the buyers have time to repair their credit so they can purchase a home. It is an option, the renters can always walk away if the terms aren't satisfactory and they have restored their credit. I have a home that I would work out a rent to own with the right people.
Either way, it is very likely you will need to have some cash available for a down payment. It could be a few thousand dollars to a larger sum. You could be fortunate enough to have someone who would accept a larger rent payment with part of that going towards the purchase.
Every scenario is different. Just be persistent and explore your options. Best of luck!