May I Use a Normal Bottle for Holy Water?

Sure you may, but just make sure it is clean. There is no rule for storing holy water at home except that it be used reverently. Often a nice bottle or container is more beautiful than a cheap plastic bottle stamped with the words “Holy Water.” Such things may be useful, but they are not required.

In the liturgy, there is a vessel for holy water and a sprinkler as well, but this is not a domestic requirement. There are holy water fonts you can buy to hang on the wall, usually by a doorway, that make it easy to bless oneself. These are smaller versions of the ones we see in churches.