Communities throughout the world can clearly benefit from a little help managing runaway dog populations. To exponentially accelerate results why not consider the following 3 points:
1. Permanently and individually identify the dogs handled.
2. Leave a record of activities performed with the community.
3. Work with communities that have a strong dog champion.
This way, unrelated groups working in a community over time can assure some continuity and avoid spaying a dog already spayed.