That magnetizer would be hard pressed to do much of anything to an Alnico magnet. Inside the pyramid is a rectifier for the mains voltage and the bulbs are there to dissipate the power in the coils after the voltage is switched off to avoid a big spark. Since all the magnetizer has to work with is the mains voltage, and since I=V/R, the amount of current, and hence the magnitude of the field, it can generate is modest. A tired Alnico magnet will be somewhat better off after using this magnetizer, but worse off than it should be.