Close. *I* would FIRST clean the area with a wax/grease/whatever removing solvent (like PrepSol or your PPG product) so you don't somehow rub/sand something (that will compromise adhesion) down into the paint.
So it's basically: Clean per usual, then clean the area with solvent. Scuff with abrasive/derust. Clean again and rust convert if needed. THEN start your touching up.
So YES, get the small can of prepping solvent. Handy stuff to have around.