Thats a good way and basicly right.
What I do is ask the earth first and than lay the oblect againts the earth ( dirt, sand, grass) and place your receptive hand over the object. Draw earths energies into the object, dont let them go througb and into you. Wont hurt you and is actually good for you but defeats your purpose. Than when the object feels saturated imagin a seal over the object keepin the energies in. Thankthe earth. To keep energies in the object
Wrap it with a blacm cloth.