The Mercury beeja mantra is "Om Bram Breem Braum Sah Budhaya Namah". The classical count is 9,000 repetitions, built up over weeks from one mala of 108 a day, and Wednesday is its day.
Mantra is the safest of the classical remedies: it can be started today, costs nothing, and cannot be worn against the chart the way a stone can. The Sankhya — the prescribed number of repetitions — is completed over weeks, beginning with one mala of 108 a day and building up. Sincerity matters more than arithmetic.
The Budha mantra is chanted on Wednesday; the Vishnu Sahasranama is used for Mercury too, since Vishnu is its presiding deity.
A weak Mercury shows as scattered thinking, careless speech, difficulty finishing what was started, and nervous restlessness. Wednesday practice and service to students are the classical response.
The classical Sankhya is 9,000 repetitions, completed over weeks rather than at once. Begin with one mala — 108 — a day and build up; sincerity matters more than arithmetic.
Wednesday. Fasting, charity and mantra japa for Mercury all belong to that day.
The mantra, the weekday fast and the charity are safe for anyone — they address Mercury without amplifying it. Emerald is not: a planetary gem strengthens whatever the graha is already doing, so it needs a chart reading first.