Carbide Burr bits good source?

I got all my carbide bit at swap meets, they are usually $1-5 a piece and the guys has tons in all shapes and sizes. Not sure if they are old Boeing stock that the guy lifts (local C-17 production here) or what but they have worked so far. Many could be HSS but I may not know the difference. Someone told me to put wax on the AL used bits to keep them from loading up?