Foreclosures of tax liens might be the best way to clear title to some of these properties. In Texas (and I suspect in all states), tax liens are superior to mortgage liens. Therefore, foreclosure of a tax lien eliminates all mortgage liens (even if the tax came due long after the mortgage was filed of record). It does not matter who is living in the property sold at a tax sale (people in the armed forces might be an exception, at least during a deployment), the foreclosure of the tax lien cuts off all other liens and all ownership claims. Some states may allow a certain time after a tax sale during which owners or lienholders may redeem the property; but I am almost certain that Texas does not have a redemption period.
So, the best strategy might be to stay in the house, pay neither mortgage nor taxes, and bid on the home at the tax sale, thus clearing title to yourself. Noooo, that can’t work, can it? There oughta be a law....