How much current is being transferred from the earth's surface through the wire to an Earthing® product?
There is no constant measurable current flow beyond the instant equalization charge transferred to the body when a person makes contact with an Earthing® product.
Once your body is grounded, the rate of influx changes, and you continue to absorb enough electrons to maintain the same electrical potential as the Earth and to restore what is being lost as a result of ongoing metabolic processes within you.
This amount of electrons varies significantly between people depending upon their lifestyle and activity and is extremely difficult, if not impossible, to measure.
