Keiko = misogi
To me, keiko is misogi, or has that effect. Regular training contains the cleansing/purification. It is a matter of attitude.
It is also a matter of letting your spirit flow, extending beyond yourself, and enjoying equally to be uke as well as tori.
We usually start our classes with a short mokuso (zazen), and end them the same way. The former opens up for misogi, and the latter completes it, bringing a warm sense of gratitude.
This, my first Japanese teacher Ichimura sensei pointed out. I stick to it.
I would say that when you practice wholeheartedly, misogi just happens - probably whatever it is you practice. Being aware of it increases this effect somewhat, but not necessarily that much.
Like in Zen, there is so much that works the best when one is not consciously striving for it.