Since the early eighties, I have really liked using multiple baits but on more than one hair, and this idea is becoming fashionable right now - but there are endless variations that would amaze you. The advantage of many forms of multiple-hair types of rigs, compared to many more standard hair rigs, is that you can get your hook inside the mouth of the fish before it even realises it has a hook attached to baits, because the hook is that much further in front of the baits, so goes into the mouth before the bait!
Most anglers are fishing with baits fairly tightly next to the hook, or fishing baits that get sucked in followed by a hook behind. In both these situations, wary carp can either hold baits in their lips and play with a rig to feel for a hook, or take the bait in but reject it when they sense the hook for any reason.
Looking at the bigger picture, if you put a thousand anglers on a set of pressured carp lakes and do not even let them use hair rigs of any kind, then carp will get caught. But if you say to them you are not allowed to use any currently fashionable or conventional rig at all but must invent your own new versions, that may or may not have multiple hairs or multiple baits of literally any kind, then actually catches will improve massively because the fish will not know what has hit them!
The recipe for success is simply to by-pass any reference points that carp have come to associate with danger, and in this case with hooks and conventional or standard baits and rig set-ups - so be different and reap the inevitable rewards. Personally, whatever is fashionable in the magazines are things I would avoid or simply adapt in my own way, so I am not replicating what thousands of my fellow anglers will be doing next weekend!
The fact is that most readymade boilies or pellets have very similar shapes, whether round, barrel or pellet-shaped. When you fully appreciate that fish are practicing 24 hours a day at detecting hook baits shaped like this, and you actually see the behaviours and feeding motions carp use to avoid getting hooked, it basically makes you see how vital it is to be different in order to not let carp use their tricks so easily. For instance, on so many so-called anti-eject rigs, carp can be seen to actually pick a bait up, sit upright slowly, or spin, shake or do other tricks like lift up the rig or lead with a fin, then up-end and dump the hook and bait back down again. This kind of thing goes on all the time with heavy leads and semi-fixed rigs, for instance.
Read Tim Richardson's full article here