What makes them so effective in even the most trying of conditions is all the single elements coming together to do different things.
The hook baits are rolled with a soluble food grade dye, then the booster liquid is layered by hand over a period of time until it has soaked to the core, the colour and flavour will wash out of the baits over time in the lake, they have been purposely designed this way, if your popups still smell and look the same after twelve in the lake are they actually doing anything at all?
Secondly there are EA based flavours leaching out which stimulate changes in the Ph of the surrounding water column which a carp can detect.
Essential oils are added which rise up through the layers carrying with them the blend of real fruit flavours that have actual taste and glycerine based flavours and Esters that disperse and drift around with the undertow. When submerged they literally pump out food signals into the water and you can see that happening in a tank test. Real multidimensional hook baits that pull carp down towards them like a homing beacon. It's almost as though they can't not eat them.