This is not financial advice, obviously.
I think hes making a supremely bad call trying to get those people to sell a real asset homestead in a good location just because of debt. in the current situation the only path that can be taken is papering over any crash with money printer. This will end up rapidly devaluing their debt to the point they will basically be getting dirt cheap primo property so long as they can float through the fixed payments long enough. People in weimar era germany that bought tons of assets on debt made out like bandits. Maximizing Debt is a good strategy if you dont hit ruin between now and the blow off of inflation. If they have savings to cover a few years of payments they should be good once the next crash hits
He does not make that specific recommendation. As to Weimar, there was a specific tax https://de.wikipedia.org/wiki/Hauszinssteuer introduced to harvest some of the value gained via paying off real estate mortgage during hyperinflation.