Glowmax has a glow powder mixed in, making it an attractant and luminescent for evening and midnight fishing.
Not only does it have natural feeding stimulants, it also lets off light at a certain wavelength appealing to squid. The "taste and scent", and on top of this "light" from the spray stimulate the squids smell, taste and sight senses to get them feeding.
Using a bright flash of light on a squid lure that has been sprayed with Glowmax Fish Spray is the most effective way to get a strong glow, which is great for nighttime and deep range fishing.