If you want to see this ASL thing in action in an ESL classroom, check out this video, Amazing Discovery from Daddy Ross Preschool, on YouTube. Val is from Argentina and her first language is not English. Being a seasoned ESL teacher of young children, she has always used gestures faithfully in her teaching but she was also looking for something else that might help in her teaching.
When she came across information about using ASL with hearing toddlers, she decided to do an experiment with her two preschool ESL classes (morning and afternoon). With one group she kept using gestures as she had always done. With the other group, she started using ASL signs instead of the gestures she had previously used.