@yonny
Nicely said.
One thing I noticed when air drying baits to get them rock hard, is they took on water (or other liquids) and got softer quicker than baits straight out of the freezer. It meant they could actually have a faster breakdown time than frozen or 'normal' boilies, which could be an advantage at times.
Ah, the washed out baits concept, supposedly making the carp think they are safe as opposed to freshly introduced.
I never noticed an advantage over freshly introduced straight from the freezer, although I did occasionally have a fish that took a bait that had been in the lake for 2 days untouched, unmoved and left in place, fish that I think were wary of new bait, even the disturbance of putting any bait on the spot.
One particular example was on a 3 day trip to Brackens Pool where the left hand rod produced 4 or 5 fish to 20lbs, all on stringers fished to the treeline opposite.
My right hand rod produced only 1 fish, a 30lb mirror that was previously uncaught at that weight, but I had left it alone for 48hours after lowering it in to the tree line to my right.
Now mixing @framey and @yonny's quotes, when bites come hard to get on your food bait boilies, it can help by increasing the amount you prebait, or put in at the end of the session.
I think carp can get used to and avoid just a few baits and getting hooked on your hookbait. By increasing the amount of prebait, and potentially the free bait when you fish, you reduce the chance of them inspecting and checking every one.
That inspection of baits is why rigs get developed or changed, because the carp can learn to avoid a particular situation.
Some is because we simply can't afford to put in more bait every trip, so need to come up with other answers.
The more you can afford, the more the fish rely on it, and a basic inefficient rig will still catch.