In Jain Dharma, beej mantra is not generally considered the primary or preferred साधन for nirjara.

Nirjara is mainly attained through:

• tapas (austerity),
• samayik,
• pratikraman,
• swadhyay,
• vows and restraint,
• pure conduct and right faith.

For punya bandha, auspicious activities done with pure intention can create punya, but in Jainism the real goal is moksha, not just accumulating punya.

The most revered and universal mantra in Jainism is Namokar Mantra / Navkar Mantra. It is preferred over beeja mantra because it is aligned with Jain principles of:

• ahimsa,
• vitarag bhavna,
• devotion to the Arihants, Siddhas, Acharyas, Upadhyayas, and Sadhus.

So, in short:

• For nirjara: beeja mantra is not the main or preferred method.
• For punya bandha: mantra can support purity of mind, but right conduct is more important.
• Best Jain practice: Navkar Mantra, samayik, pratikraman, tapa, and restraint.

If you want, I can also explain the difference between punya bandha and nirjara in Jain philosophy.