Long version:

We're trying to reach a highly localized but difficult to access audience and get their opinion on several potential design concepts. With in-person engagement restricted, we are working through churches, community spaces like laundromats and gas stations, and the site itself (where people walk by) to post images of the concepts and gather feedback.  We have been assured that nearly everyone in the community has some kind of mobile phone, but not all are smartphones, so we want to do an American Idol-like poll where you text "yes" or "Y" to a number associated with each concept to rack up votes.

All of the services I've been researching assume you want to capture incoming numbers and legally require an opt-in so you can send them messages. I don't care about capturing their numbers, and I don't want to send anything out. I just want to know which concept they prefer, in a way that minimizes the spread of COVID and is accessible and fun for them. And I only need one month of service. Apparently this is not the way text marketing works.

Anyone have any suggestions for non-web-based, non-smartphone-dependent text voting platforms?

Thanks in advance for your advice!