Mortgage mod workaround? Move out and rent.

[catleg]

This may be stupid and obvious, but do we know if anyone has tried an end-run around the rule/law against modifying a mortgage on a primary residence by simply moving out for a while? Suppose 2 prospective ch 13 debtors arranged to rent their underwater houses to each other, and legitimately move themselves as well? File taxes on it as a rental property, take depreciation (IRS will love this), etc. There's got to be somebody out there crazy enough to try this.