Natural baits is an option but i have reduced how many times a year i do this, due to alot of faith in pellets, you can use and feed smaller ones and also due to the fact that depending where you are fishing, you can be constantly disrupting the swim buy hooking dace/roach with maggot/caster, unless prepared to get pints and pints of the stuff in. The sometimes stiffer rods/tips needed perpetuates the bite indication aspect and sometimes not even realising a roach/dace/small bream is on does little to help the swim too. This time of year and in low water i will only go to a 12mm bait if there are silvers getting in on the pellets. I don't mind chub as my second favourite species either so i don't go for the longer hair to avoid them, in fact a longer hair worries me anyway as due to the way Barbel feed (they mouth the bait to inspect it, which is the point at which you are looking to hook them) i am convinced you miss hooking them on occasion. So many people believe that Barbel, despite being a cyprinid, suck baits up by creating a vacuum in their mouths, however they don't.
On that aspect too and if using smaller baits especially on a longer hooklength, the Barbel don't turn away, like a Bird does with a big food item to eat it in peace, they look to continue to feed, so sometimes looking for those indications is vital, although aided by the shorter hair where you will then get that big pull as they feel the hook on the inspection and run.
On the sweetcorn thing, very selective imo, Barbel can run a mile from it, especially in clearer water and is one of the first baits to blow usually. Again dependent on how much has gone in of course, but that's it, on these busy stretches you don't know what has gone in and what hasn't, ease in with any bait is my advice and you can sometimes be surprised, hence pellets in with small amounts of groundbait fished on a slow release is one bait that allows me to avoid the issues i mention.
If two rods then a sleeper rod with meat early morning or last thing and small boilies during the day can surprise you at how much little bait or feed can work, when it does work, which i have found it does, it emphasises that the Barbel, especially in these conditions aren't getting stuck into, or are even shying away from large amounts of and large baits.
I don't target large Barbel, a Barbel is a Barbel to me and sometimes they come along, and my top 3 PBs have come on, 8mm meat, 8mm pellet and double maggot respectively (after feeding possibly 4 pints of maggot and on a day/swim where there were no roach). These weren't caught by design, any Barbel could have picked up the bait, again though, less can be more.
Most of my experience is on busy stretches and in the daytime and when Barbel respond early or late and significantly overall, slow up in the day, especially in current conditions, it tells me a more stealthy approach is needed. Water level and clarity i have found to be one above light levels in importance unless in a place where Barbel will reside regardless, then its down to triggering them, so biggest advice is stick at it and put the hours in, as the OP mentioned, learn something from any session, good or bad.
