You don't need a wire brush. You're more likely to delaminate the contacts with that. The easiest way to clean contacts is with a pink pencil eraser, just rub the eraser on the contacts. One thing to be careful of is if the chips get wet you have to ensure they are completely dry before inserting them in the printer. Inserting a wet chip is the easiest way to destroy them. Clean the contacts, make sure they're aligned and dry, then reinsert. If it still doesn't work it may be too late. Oh and if you're using baby wipes that are designed for skin, don't use them as they often have lotion and oils which will leave a haze on any smooth surfaces they encounter. Oh and I would also wipe the print head contacts with a q-tip dipped in alcohol to clean any baby wipe residue off them. Wipe them with alcohol then polish off the remaining residue with a dry q-tip.