A method that enables the post to deliver letters, flats, post cards and packages addressed to a recipient’s virtual post office box and then to be delivered directly to the recipient. The anionic diinitiators are prepared by admixing a diisopropenyl benzene compound with diethyl ether, ethylene, an organo lithium compound, and a solvent under reaction conditions sufficient to prepare a diinitiator having primary lithium alkyl reactive sites. The metal elements have a width of about 0. The relevance may be based on reference to a large-scale database containing queries from other users. The oral care agents can be released during one use, during multiple uses, or throughout the life of the instrument.