Insert a narrow, flexible brush into the hose opening. Work it back and forth, rotating as you go. This will dislodge stuck debris without needing to remove the whole hose.
The fizzing action will loosen debris. Keep the hose elevated. how to clean dishwasher drain hose without removing it
Mix ½ cup baking soda with 1 cup warm water. Using a funnel, slowly pour it into the hose from the disposal end (disconnect the hose clamp if needed—you can leave the dishwasher end connected). Insert a narrow, flexible brush into the hose opening