Drilling holes in aluminum?

[DogLoverNYS]

Not shaping specific, but....

My first post. I am very active in dog sports (agility, obedience, nose work) and spend a fair amount of time and $$ in hardware stores because the supplies and accoutrements needed for training dogs are often easily made with the appropriate supplies. Gotta love YouTube

Newest sport: scent work, which is based on detection dog work (think 'dogs finding contraband' except this is for pets who find small packets of essential oils, not bombs or drugs).

Came across these nifty fobs in which those essential oils can be hidden -- they are usually used for geocaching. They are aluminum, have a domed top. Need one hole in the top to allow odor to escape (magnet on the bottom). They are about the length of the top part of my thumb (can't post photo. Bummer)

Using a drill press, and holding the fobs in a vice grip the first 20 or so. After that, disaster. Drill cutting into the metal and tearing around the top, no holes.

Suggestions?? Warning: I'm a border-line senior woman with minimal DYI skills. Drill press borrowed, for example.