Read Ana Forrest's response:
This is a common problem for teachers. Be flexible. If chanting is strange to them, put it aside for now. Teach them how different aspects of yoga will serve them in their passions. Use language they're willing to hear: for example, coach them to use strong focus and deep breathing to access "the zone" in their yoga. This will make yoga enticing to them without holding any weirdness.
These people will benefit tremendously from the yoga, and that's what you need to keep emphasizing: how they will benefit from each pose. You don't have to teach them everything all at once, or even in the first year. It's your job as a teacher to be flexible and skillful in how you present your information. If they cannot hear your teaching, then you are wasting their time and yours. Be willing to structure your teaching depending on what they can absorb at a given stage.
Teach cues that will help them with what they are interested in, then slip in the some of the deeper teaching you are passionate about. For example, you can say what the poses are in English instead of Sanskrit, and leave out the chanting for now. Consider doing a workshop to bring in the other aspects of yoga later, after your students have begun to build a bridge of trust with you. Give them time to see that you have something to offer without threatening their paradigms.
You appear to know how to teach them the benefits of yoga, but you're running up against what you believe you are supposed to do as a yoga teacher. Put aside the beliefs that aren't working with these students and teach what does work—teach yoga.
Ana Forrest is recognized worldwide as a pioneer in yoga and emotional healing. Born crippled, her own life trauma and experiences compelled her to create Forrest Yoga®. Her focus in Forrest Yoga is to guide the student in the sacred exploration of truth, healing and "the Great Mystery." She is a well-known contributing expert to Yoga Journal and other national wellness publications. She travels internationally teaching at yoga conferences, workshops, and teacher trainings.