There are so many ways you can sterilize a baby bottle. You can use a microwave, boiling water, warm soapy water in the sink, and the dishwasher. Just make sure you clean correctly and avoid any shortcuts.
Apply gel all over, then dry your hair, lifting up and back to create volume up top and smooth the sides back, tucking them behind the ears. Finish with hairspray.
That would really just be a large spray bottle. If you were looking for a water gun with more capacity, I would recommend sizing up the whole project to larger...