>>29916630The way they work is that they don't actually change iv's so for breeding purposes it's useless.
However if you have your right nature, ability, and attacks on it boost away.
Unless you want to run a specific hidden power, because since it gives you the stat boost of max iv's bottlecaps don't actually change them so hidden power stays the same.
So for example my Pikachu has HP Ice which I want, but not max IVs which are the ideal stats so i can use bottlecaps to compensate but keep the HP as ice.