The most effective way to discuss fighting obscenity in the public arena is through the legal and medical arguments rather than moral ones. The courts have ruled that communities can curtail sex shops because of evidence of harm, not because of moral objections, no matter how widely held.
When talking about the need to pass obscenity laws or sexually oriented business regulations, you can highlight a series of land-use studies conducted over several decades that show the negative secondary effects of such businesses.
It's also important to make public officials aware that they have been elected to serve the needs of the community. If your city council is not responsive to the community's desire to pass sound, legal protections, you have an opportunity and an obligation to remedy that situation at your next election.
