It won't be better for Moon Jae-in to hurl bottles in which intimidating messages against Kim Jong-Un regime is written.
But, it won't be an issue to hurl ones filled with rice, seeds, or any other kind of commodities used in daily lives. That has nothing to do with criticism on North Korean regime.
Rather than that, it even helps general people in North Korea.
Instead of making them stop sending all the bottles forcefully, it would be better to check items inside the bottles before hurling them.
Just sending food or commodities is the same as UNICEF does in developing countries.