Letter jackets are often made of wool and have leather sleeves, and cleaning strategies for the two materials aren't the same. Therefore, cleaning a smelly jacket may be a two-stage process. Simply throwing the jacket into the wash will ruin the wool and probably damage the leather. Dry cleaning might cause the color of either the wool or the leather to run. Fortunately, there are several home remedies that will remove the smell.
Wipe the leather sleeves of the letter jacket with a weak solution of water and white vinegar. Allow them to dry, preferably in the sun.
Store the jacket overnight in a sealed hamper with a box of baking soda.
Wrap the dry jacket in dry newspaper or packing paper and store it overnight. The paper will absorb odor.
Seal the leather arms of the letter jacket in plastic bags with rubber bands.
Add a few drops of dish detergent to a sink half full of hot water and stir gently.
Place the letter jacket in the water gently and allow water to penetrate it for about five minutes.
Remove the jacket from the water and place it in warm rinse water. Remove it from the rinse water, allow it to drain excess water and place back in the rinse water.
Drain the rinse water and allow the jacket to drain in an empty basin or sink.
Place the jacket on a towel to absorb excess water.
Hang the jacket up to dry or tumble-dry it on the air-only setting to avoid shrinking.
After cleaning the jacket, condition the leather with real linseed oil, clear liquid shoe polish or leather conditioner.