In the dilution of acv to water a chicken would drink, there is little probiotic properties, if your water is from a municipal source, the sterilizers in the water will kill anything left. As I said, it wouldn't help here.
Next time you clean your coop, wear a mask and scrape up the d.e, it will cause respiratory issues in you and especially them with their larger, more delicate respiratory system.
It's also not even close to environmentally friendly.
I'd stop the treats and give them a worming with Valbazen goat wormer.