While bondage is a powerful experience for many, I would hesitate to proclaim it as a no-fail dispatcher of endorphins, same with kneeling.
"Enter endorphins: your own private narcotic. Endorphins are neurotransmitters, chemicals that pass along signals from one neuron to the next. Neurotransmitters play a key role in the function of the central nervous system and can either prompt or suppress the further signaling of nearby neurons.
Endorphins are produced as a response to certain stimuli, especially stress, fear or pain. They originate in various parts of your body -- the pituitary gland, your spinal cord and throughout other parts of your brain and nervous system -- and interact mainly with receptors in cells found in regions of the brain responsible for blocking pain and controlling emotion."
Not to be a wet blanket or anything, just to say that different people react differently - not too much is known about how it works in humans - so I'd say keep an open mind and see what it does for you/to you, but do not expect other people's experiences to be the same for you, whether good or bad.
Another thing about bondage is that as it does in fact make you helpless, you may have unexpected reactions of panic or fear, which is not to say that it would not eventually work well. This can happen even if you trust the Dom/me absolutely. Just that again, it is different for different people.