FHA is for sure not going to be an option for him, last option is purchasing from an investor with owner financing, or lease to own program where he will not need traditional financing. 

What other programs do other people use to get addresses to dispute these? 

I work with multiple different programs through our housing authority ("Section 8" and similar).

You might check with your Self-Directed IRA Trust Company/Custodian, they might have a brokerage connection capability where you can setup a brokerage account tied to your IRA, then you can with that brokerage to invest in various public market investments, in some cases stocks, mutual funds, ETF's, treasuries, and CD's.

Additionally, Fannie Mae and Freddie Mac will sometimes temporarily suspend the income cap on their HomeReady and HomePossible programs, which allow purchases with 3% down.

Its extremely important to know your numbers upfront from approved sale price, Maximum or Minimum downpayments, programs, costs, and seller credits.

Maybe look into a down payment assistance program for a first time homebuyer and house hack.

Explain your situation and see if there are payment plans or hardship programs available.The BiggerPockets forums have threads on tax liens and foreclosure prevention: https://www.biggerpockets.com/forums/41/topics/766025-surplus-funds-unpaid-taxes-in-foreclosure-saleAn experienced real estate attorney can advise you on your legal rights and explore potential solutions.Have you spoken with your local tax authority yet?

I will not name every program out there because this would be a very large reply post.

Why do you believe cheap housing is in the best interest of the public?