Well i went from averaging 5 barbel a year ( using off the shelf baits ) on the Yorkshire Derwent to 24 barbel in a season after I’d pre baited with an HNV. bait , I kept the bait going in on a regular basis , a fresh one egg mix per evening session, and whatever that was left got thrown in at the ended of the session.
I’ve seen it happen numerous times fishing for carp , location is almost secondary as they seek the preferred food source out .
It takes patience and an understanding of what your trying to achieve
Yes I know you can catch em on plastic sweetcorn etc but that’s a visual impulse thing , pretty sure they don’t actively seek those types of baits out !
Once you get em hooked on the bait there almost easy to catch.
But as Rich says it takes a venue where you can do this , it won’t work on a day ticket or busy club stretch .