Perimeter Let's face it, it doesn't matter what species of fish a flavour attracts providing it is small, for where you have small fish you can be sure the perch will not be far behind. They will stay just on the perimeter of the feeding fish, waiting for the right moment to strike. A bait strategically placed may pick them up. If a flavoured bait gives you more confidence then use it. Little and often is probably the best policy, perhaps feeding in a couple of small balls of groundbait to start with and then throwing in a little more each fresh cast.
Maggots are a good bait to loose feed with and so much the better if used over a bed of groundbait.
The one thing that I do know is that it makes the maggots wiggle more. It would make us wiggle too if we were dropped into a giant tin of curry powder. So rather than the taste and the smell it could be the extra movement that attracts the fish, but perhaps we shouldn't analyse things too deeply, but just accept it as an improvement. Now having examined baits extensively, I am beginning to feel like a modern carp angler who believes the most important aspect of fishing is the bait, when in fact it is not. Location is far more important.