Hera are some best practices you could follow:

1. Remind Amila members that in the words of Hazrat Khalifatul Masih (aba), this initiative was focused on the Amila so they can lead by example. 

2. If an Amila member cannot come to the Masjid daily due to a very long distance, at least they should come for a few days and go to the nearest Salat Center for the remaining days.

3. Respected missionaries can adjust the salat times where possible to make it easy for members to offer Maghrib and Isha during a single visit. 

4. Use the time between Maghrib and Isha effectively. Hold short dars or a QA session or provide a simple dinner. 

5. Remain punctual and predictable so a member's trust is strengthened.

We have seen these steps to work at other places. Ultimately nothing will succeed without sincere prayers from Allah the Almighty.