Putting the frozen bottles into the hot wort will work to cool it down. The hot wort shouldn't do anything to the frozen bottles.
They make an item called a rapi kool, which have a 32, 64, & 128 oz. capacity, which is designed for professional kitchens to quickly cool hot soups & stocks. I've used them with good results in this method. Been thinking of getting some to use to chill my wort.
Here is a link to show what they are