Rehabilitate and/or deter. The extent to which it is either the former or the latter depends on the country. That also determines whether or not "treating them badly" should be a feature of the justice system.
1. Early-life exposure to diverse, nonpathogenic microbes is linked to lower risk of allergies and asthma: "farm effect" (Amish vs. Hutterite study showing microbe-rich house dust associates with protection).
2. What matters is exposure to the right environmental and commensal microbes, not skipping handwashing or basic hygiene. Microbial diversity is good; pathogen exposure is not.
Budget or generic alternatives cost as low as US $0.20 to US $0.50 per marker.