never used a distress call for squirrels, have used a call that just sounds like one squelling or chattering to let the others know a hawk or an owl has passed through.useing that let me know in what trees they are in.

as for the coyotes I would say it should work.they hone in on distresed animals.
I would say a squirrel in distress call was intended to be use for preditors, and not to hunt squirrels with ; JMHO