Doktor Doom. The biggest benefit to using the Total Release Fumigators is that they are made with natural pyrethrum which biologically breaks down in a couple of hours (providing very fast re-entry times to fumigated areas and they really do not have a strong odor- which also provides the homeowner with a peace of mind as there are not any long lasting obnoxious odors lingering in the air- and does not leave any residuals.