I believe one way to safely discharge LiPo batteries to render them safe for regular garbage disposal is to fully submerge them in a saturated saltwater solutio

I believe one way to safely discharge LiPo batteries to render them safe for regular garbage disposal is to fully submerge them in a saturated saltwater solution for more than 24 hours until the cell is fully discharged(some lipo chargers also have a discharge feature). You may still be required to separate them from household waste depending on local regulations, but it shouldn't combust once the voltage is 0.