If I build a recording studio, maybe I'll line the wall with old shoes, smells like a good idea.
Do you honestly believe you would ever smell the material?
Its not like they don't clean and treat materials that get recycled.
That plastic bottle you're drinking a Coke out of might have been a garbage bag in a "previous life", but do you care?
A good chunk of the steel in a new car is recycled. Does that make it bad?
Heck, many carpets in cars are made of at least some % recycled material. Does it smell bad?