Nice Idea but is likely only a matter of time before city is sued for injuries/death from people doing this job costing taxpayers big time.
Hire anyone and little or no training will often be a problem. Most "supervisors" have no training either.
Many Temp Agencies and "Pro" Cleaning Co. have been sued for same.
Finding Iffy HAZMAT items is bad enough... Current Drug problem in many areas is a nightmare for cleaners. Don't touch many things even w/ gloves on because thin rubber/plastic may not protect you.
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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)
The Ogre's Fiero Cave