If carpets think their owners aren't looking, they sneakily begin to collect dirt, grease, and loose hair among other items needed to invent a new flavor of birthday cake. Protect yourself from obligatory taste-testing with today's Groupon: for $42, you get eco-friendly carpet cleaning for one room (up to 250 square feet) from Greenforce Clean Team, servicing homes in San Francisco, San Mateo, Oakland, and surrounding areas (an $86 value).

Instructed by the timeless precepts of their four-step carpet-cleaning process, the Greenforce Clean Team scrutinizes dingy shag carpets to pinpoint areas of disrepair and evict contaminants with mechanical efficacy. First, the estimable rug wranglers attack high-traffic areas and stains with a vanguard of heated cleansers that loosen subterranean colonies of grease, soil, and quarantined Frito crumbs to ease their impending removal. Techs then unleash a high-pressure flood of hot-water-based cleaning solution that penetrates deep into fibers before sucking both water and dislodged dirt into the clutches of an allergen-removing vacuum. Finally, Greenforce operatives wipe down baseboards and comb through preening carpets to affect a uniform, groomed appearance ideal for upcoming house parties or weddings uniting family-room armchairs.

Greenforce, as its name suggests, specializes in eco-friendly cleaning with green products, staying even more carbon neutral by donating to Carbonfund.org for each house call made. The team has been cleaning the Bay Area since 1993, when the Internet was still a young, rampaging menace, destroying hillside farms with text-based role-playing maneuvers and ASCII color codes.