***Krishna and the Name of Krishna are ONE***

Sri Shankracharya has written this glorification at the ends of the Gita (Sri Shankracharya's Gita-mahatmyam, 4), 'The Geeta should be rightly read with one-pointed devotion, for the satisfaction of Sri Krishna. No other scripture is necessary if one take shelter of the Geeta. The Geeta emerges from the holy lips of Sri Krishna and is one with Him.'

It is not material sound. In material sound, you will find that the thing referred to by a sound is different from the sound itself. If you utter: 'water, water, water,' the water word is not the water-thing. The word 'water' refers to a thing understood to be water. In this world you will find a difference between the word 'water' and the object referred to by the word 'water.' But Krishna and the Name of Krishna are one and the same. Sri Geeta and Sri Krishna are identical. So, by taking shelter of the Geeta we can come in contact with Sri Krishna. If we read the Geeta, we will obtain devotion to Sri Krishna.

I think, apart from chanting on beads, while at work/home, you can chant as under:

There are no rules in chanting of this Mahamantra, You can chant anytime, anywhere. You can chant on bed, on chair, before bathing, in bathrooms, while driving, while walking, while waiting for someone, while getting up from bed, before eating something, before sleeping, and so on. For e.g. when you wish to get up from bed, just say

Hare Krishna Hare Krishna Krishna Krishna Hare Hare

Hare Rama Hare Rama Rama Rama Hare Hare,