Exhaling DMT vapor is pretty poor form

You could try running an ozone generator for a while but ozone will degrade a whole host of other materials, principally any organics with a double bond in the structure. You would have to ensure that no-one entered the space during the ozonation process either - ozone is highly toxic. Chlorination would be an even worse option.
I don't think anyone will ever have smoked enough DMT inefficiently enough that an active dose could be absorbed from ambient surface contamination. Just what exactly are you worrying about? Law enforcement?
“There is a way of manipulating matter and energy so as to produce what modern scientists call 'a field of force'. The field acts on the observer and puts him in a privileged position vis-à-vis the universe. From this position he has access to the realities which are ordinarily hidden from us by time and space, matter and energy. This is what we call the Great Work."
― Jacques Bergier, quoting Fulcanelli