Hydrogen peroxide is an excellent product for debriding (cleaning crusties) off of the jewelry. It is also an invaluable tool to dislodge pus from an infected piercing. In the presence of bacteria, oxygen bubbles are released, causing the peroxide and pus to foam and mix. If simple washing is not clearing the pus, washing with peroxide until the foaming stops is reccommended.
Excessive cleaning with any agent will remove natural oil from the skin. Hydrogen peroxide is particularily bad for this. Watch for irritation, dry skin and/or local redness (chapped skin) around the piercing. Do not confuse this with an infection. It is temporary and will usually be relieved immediately by stopping the use of peroxide, and by applying a moisturizing creme around (but not in) the piercing.