Om Namah Shivaya on an asli tulsi mala is both traditional and spiritually meaningful. The tulsi mala made from the sacred basil plant is revered in Hinduism for its purity and connection to Lord Vishnu but it is also perfectly suitable for chanting mantras dedicated to other deities including Lord Shiva. https://www.radheshyamtulsimala.com/how-to-handle-broken-tulsi-mala/