Use such tools as privacy screen and permission slips. Open access in a public library maybe wishful thinking. Put your institution's energy into excellent service. The Internet Filtering Project evaluated how internet filters performed in real life. Prurience was presumed and project was designed to get librarians to assess new information tools.
Pornography is the issue with filters non-bomb building.
Presumed that filters were just another tool libraries use to organize collections. It unrealistic to assume that when people go looking for sensitive information on the Internet that they will not find it. Filters are part of the answer. Run filtering software product for a month and see what your patrons are finding. Look for filters that have feedback tools so that you can determine what sites are blocked.