Chickens ♡
I often thought of the blue pool thing but, was also thinking I would have the same results, wasted money and effort - and terrified chickens. I also thought a Pasco liner may work, be a little less terrifying, plus I could make it shallow and to whatever size and shape I needed, but, I have done neither. Instead I ran a hose up to a tree and turn it on low. I get to give slow needed soaks along along with drawing up bugs for the chooks. I even toss in frozen fruit in the puddles during the worst of the heat.
If you go through the effort and find somethings that work, please let us know♡♡♡!!!
I wonder if you put in transitioning objects of interest, like logs and bricks so they could hop and get used to getting their ankles wet first....