Hi Avraham,

Great question, because it helps understand the two different kinds of places that are considered as places that we know that they do not have Chametz in them. One, that usually Chametz is not brought there at all, and the other, that even if Chametz is brought into that area or room, we can assume that it doesn't exist by now, or that even if the Chametz was around, it was not shoved into inconvenience places.

The places mentioned in Beraysa are places that it is theoretically possible that Chametz will reach there, but because they are physically not comfortable places, therefore we can assume that there is no Chametz there, and not because they are simply not used to bringing Chametz into this kind of place.

Chorei ha'Kosel - holes in the wall that might have been used as storage, but are too high or too low, as the Gemara itself immediately says.

Gag ha'Yatzia and Gag ha'Migdal - places that store food, but their cover or top is not suitable for use.

Refes Bakar and Lul Tarnegolim - Chametz is brought there for the cattle and chickens, but we can assume they ate it all.

It is true that on the hay storehouse and the wine treasures mentioned in the Beraysa, you can ask your question, but perhaps the Gemara is mainly referring to the first examples.

Best Regards,

Aharon Steiner