For aluminium, you'll need liquid of some kind, otherwise it's likely to stick and cause you big problems.
However that liquid can be as simple as a little spray of WD40 occasionally, combined with just enough air flow to blow the chips away. All you need to aim for, is to keep the cutter coated with oil, and get the chips away from the cutting edge so they don't get recut.
You don't need a large compressor, however I'd doubt if an aquatic pump will have enough flow/pressure to clear chips, especially if it involves blowing them out a recess/pocket.
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My suggestion would be to beg/borrow/steal a compressor of someone, so you can get an idea of what you're requirements would be.