You can try this video sound from your home OR The owners could try to condition them by using a compressed air and spraying it into the air every time they bark. It essentially breaks their focus - redirects them. Gets them to associate bark to this weird sound. youtu.be/pkIeFYD1xVA?...

High Pitched Dog Whistle Sound To Stop Dogs Barking

YouTube video by n Beats

Oh wow I wonder what they'll think of the sound, thank you. The owners are not about the training, they have given up and just accept that they have a pack of feral scary sons menacing the village.