Does it matter in which direction silver, iron or other metals are placed underground?
No. Direction rules for metals apply above the ground, where the cosmic energy of the planet's location acts, not underground. If they applied underground, silver would be found only in the North-West, gold only in the East and iron only in the West. Iron rods are laid through the whole slab anyway, so cutting a zone with an iron strip means nothing; learn vastu with logic and science.
Related questions
Which planet and metal belong to each direction, and why place that metal there?
In Vedic vastu each direction represents a planet: East is the Sun (gold and copper), South-East is Venus (white metal), South is Mars (copper), South-West is Rahu-Ketu (panchdhatu), West is Saturn (iron), North-West is the Moon (silver), North is Mercury (kansa and brass) and North-East is Jupiter (gold and brass). The planets cannot be held in a fist, but their energy can be deposited in the home: the material representing a direction's planet captures that planet's energy there, multiplies it, raises the power of the place and nullifies negative energy.
How are silver and gold added to a dowsing rod?
On a Guru Pushya or Ravi Pushya yoga, have a goldsmith mix them into the copper and make the rod. If that cannot be done, take ready-made rods and have silver and gold fixed at their solid point.
How do we find the angle and composition of the sun rays falling on a house in each season?
This is taught while preparing maps: for summer, the rainy season and winter, the particular angle at which the rays strike and their composition are worked out, so that openings and walls can be planned for the maximum benefit without demolition.
Shikhi lies in the pishach bhoomi, so where should one sit for its jaap?
One cannot sit in the pishach bhoomi itself. Sit facing East in padmasan or sukhasan, project your vision to the devta's place as if through a telescope and visualise it, and chant the Shikhi mantra on a silver or gold mala, as many rounds as possible, in the period up to 3:00 am; with aahuti the mantra ends in swaha. It helps when the mind is blocked, business ideas do not come or children cannot memorise. Exact words: refer to the class recording.
Why do the same treatment items give results for some practitioners and not for others?
Often because the items, such as pyramids or silver and gold nandavart, were not placed at water level. Unless an item is set at zero degree the gravitational force does not act on it, and it gives no result however valuable it is.
A South boring was abandoned and a new one dug in the right place. How should the old pit be closed permanently?
Put five haldi, five supari, panch ratna and a silver swastik into it, then fill it completely with sand.