Sorry I did not make a very thorough reply. I was concentrating on getting pictures downloaded from the camera that has been missing for a while.
Yes they help. Patrolling the orchard and garden often catching maggots before they eat into the fruit.
The most important is to collect all fruit. If an infested one falls to the ground the maggot will burrow into the ground form a protective covering and emerge the next year to start the cycle over again. Composting the fruit therefor may not break the cycle. It needs to be cooked hot enough to kill the maggot.
This fruit/insect cleanup is why many run chickens under their orchards. I saw fruit size double with chickens and ducks under my plums, though I also did improve pruning and fruit thinning as well.
While clay or other organic sprays can help in the short term, anything that does not support an ongoing predator population will require ongoing and increasing intervention. Pests are their predators’ food source, and any drop in the pest population will rebound faster than the predators’ with most human interventions. Ways we can help are with soil building to support the trees immune system, and with predator habitat. This can be birds (wild or domesticated) and insects (brush piles and fresh water); reptiles and amphibians (rock piles and fresh water); mammals (pigs are also great for fruit cleanup, again requiring fresh water); fungi (woody debris) or bacteria (bug juice made with pest carcasses cultivating the pests’ pathogens). In combination, these habitats will maintain a more diverse and self regulating ecosystem.
This is all just my opinion based on a flawed memory