Please accept my blessings.
All glories to Srila Prabhupada.
To get the full benefit of chanting on japa beads one needs to follow
these four principles:
1. No illicit sex (sex only for
procreation)
2. No meat eating (including fish and eggs)
3. No intoxication (including coffee, tea, and tobacco products)
4. No gambling (including mental speculation)
I hope this meets you in the best of health. Your ever well-wisher,