Parafin in my usual choice, you really don’t need much and if the chips are left for a day it will evaporate. I have recently taken to using a fully synthetic cutting lubricant when doing long milling jobs on the CNC but if just hand (brush) applying I would say stay with the parafin. Cutting dry you may find the surface picks up.

Certainly worth getting say  6mm and 10mm Carbide cutters intended for aluminium either two or three flute and standard length as you can run them fast and take off quite a lot. Best to use a cut that uses most of the edge so 15-20mm and 1mm sideways is possible with the 10mm and 10mm x 0.75 for the 6mm. Again just a drop of parafin before each pass. You might want a long one to get into the base but they can chatter a bit more so reduce the cut.

I use a tiny amount of WD-40 brush applied when cutting aluminium. I use a two insert indexible end mill for facing surfaces (I’ve a small mill). A quick wipe with a brush over the surface and inserts before each pass. For solid mill I just “wipe” the cutter with a flat stiff bristle artists brush. The long handle compared to a acid or glue brush keeps hands etc away from cutters and moving parts.
I bought a 5l container of WD-40 years ago. it goes a long way. Parrafin will also work. If you don’t like the smell you could try de-odorised white spirit with 1 or two percent of oil added.

Robert.

Problem is if you don’t use lubricant and a bit of swarf sticks to the cutter on the final cut it’s too late.