Public bathing facilities was an option in Rome
Why not return to the days of public bath houses without the lead lined aqueducts of Roman times?
While traveling in warmer states I noticed that there does seem to be a larger percentage of homeless people than in colder areas and it would add to the need for housing and restrooms. Colder climates have warming rooms for the small numbers of homeless located in their areas - just spending one night at a rest stop in a warm urban area showed me that the transient sleep in the car population would overwhelm the warming room located in the rural location. Locating a camp ground style public bathing and rest room facility near areas where homeless people congregate/are allowed to congregate might support public health and the homeless person's ability to find a job while trying to survive on limited income. It is hard to find a job when just trying to find a restroom is difficult.
Incorporating health research into the benefits of magnesium sulfate salt baths or foot-soaks for substance abuse and chronic illness or mental illness populations could be a coordinated goal that might help fund the facilities. Magnesium deficiency is associated with anxiety, paranoia and anger that can progress to rage and violence. Magnesium deficiency is also associated with many types of chronic illness conditions and is more of risk with a variety of commonly abused substances including alcohol. The advantage of providing it in a bath or foot-soak is that the intestines can become less adept at absorbing magnesium and the kidneys more prone to excreting it in favor of calcium being better absorbed by the intestines and retained by the kidneys.
Headaches and other types of chronic pain and muscle cramp conditions can also be relieved by a magnesium sulfate (Epsom salt) or magnesium chloride topical soak or hand-cream type mixture. Working with a healthcare or insurance provider to test the efficacy of simply providing easier access to topical magnesium sulfate or magnesium chloride could help subsidize a homeless bathing facility or making the facility simply a pay to use community park addition could help subsidize it. charge a small fee for use of the shower or bath stalls. Truck stops charge around $12-14 dollars for use of nice quality shower area - that would likely be too costly for a homeless/low income person to be able to use very often. It is likely that a more campground style bathing facility could be provided for a lower cost to the individual purchaser of time in the facility while supporting the goal of improved public health. Making it a fee for use facility could help support cleaning staff for maintenance of the facility.
If research goals were incorporated then more support staff would be required to educate and obtain permission from participants in the project. Ethical medical research requires full disclosure of any potential risks of a research project as well as obtaining consent from the participants. The topical use of magnesium in the form of a bath or foot-soak can become too much of a good thing if used excessively or someone fell asleep in the bath. Twenty to forty minutes every few days is a beneficial amount when about a cup of Epsom salt is used in a bath or foot-soak.
Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.