What are your views of training the Sandbag?
It can help you time your footwork with the punch’s moment of impact. Oldjong, you’re right, this type of training also helps western boxers.
One other point…
It will allow you test and strengthen your structure. Try hitting a bag with incorrect structure, let’s say a bent wrist, and see what happens. 
Matrix
the wall bag (we use gravel) helps
*stance
*waist
*wrist strenght
*knock down power ( more to do with stability)
*teach ecconomical movement
*strenghthen little stability muscles in arms and wrist
*relaxation
*single punch power (without adding power of hand withdraw)
facing
*bipasses the natural reaction to not hurt ones self. most people hit like girls because they are pulling back as they dont want to hurt there hands.
conditioning is only a byproduct of punching the bag.