Hello s1m0nw and welcome to the forum.
Leather absorbs odors as you know but the good thing is - with time – it will go away.
Here is a recipe for cleaning leather using a favorite essential oil. Remember the scent you choose will remain for awhile so pick something you can live with. This recipe can also be used for clothing as well.
In a one gallon bucket fill half of it with water and add the following:
• 3 1/3 cup olive oil
• 1/3 cup castile soap
• 40 – 60 drops essential oil
• 8 – 12 drops grapefruit seed extract
Mix all ingredients together and put a smaller amount in a spray bottle and shake well. First test this mix in an inconspicuous spot first and wait to see if there will be any reaction.
Spray the mixture then rub in a circular motion using a soft cloth. Get a new clean soft cloth and buff to shine.
Use ZeoliteZeolite crystals can help to eliminate stubborn odors. Zeolite is a natural mineral that will absorb moisture, fumes, and odors. It comes from volcanic ash and works much the same way that charcoal does in removing odors.
Zeolite comes in a mesh pouch that can absorb odors for a period of time and can be recharged by being placed in the sun or microwave. You can find Zeolite in many grocery stores, farm and garden stores, home improvement stores, and online stores.
Using this method you would put the Zeolite under the couch to absorb the stubborn odors. Here is a website where you can get more information if you’re interested.
You can purchase
Zeolite from Amazon.
Hiring a ProfessionalCheck the tag on your couch before you embark on a homemade cleaner. Some may state it should only be cleaned by a professional. This may be especially true if you purchased a warranty. Some warranties will not cover the cost if you have tried your own methods first.