Charities should always be 100% transparent. There are standards for this. The only way to know if a charity is worthy is whether they are successful in their mission, which should be measurable like a KPI. Besides that, a third party auditor is necessary not only to root out corruption in the organization, but to ensure they are solvent and whether their recipients do not end up in recidivism. Its not a simple matter of throwing money at a problem, most of the time money makes the problem worse. If you can find a worthy charity, you are fortunate.