What type of exorcism can I perform on my house so that it will no longer smell like old person?

My in-laws visited for the long weekend and no matter how hard I scrub, vacuum, dust, mop and steam clean...it still smells like peppermints and Aspercream. It's like their old person stench has permeated the walls. I'm afraid I might need to sell the place, but I can't afford a new mortgage every time... show more My in-laws visited for the long weekend and no matter how hard I scrub, vacuum, dust, mop and steam clean...it still smells like peppermints and Aspercream. It's like their old person stench has permeated the walls. I'm afraid I might need to sell the place, but I can't afford a new mortgage every time they decide to pop in.

Semi serious question....what else can I try to get my house smelling right again?
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