My Parker frontier is alas misbehaving and looks like the nib and feed unit was not meant to budge. Usual methods of using bulb and water does not work because the sucker is clogged with red ink. In desperation I have ordered an ultrasonic cleaner from amazon the kind used for watches and eyeglasses because it seems like if it accommodates glasses it should fit fountain pens as well.

Any cautions? Do inlaid nibs come unglued? Has anyone any recommendations on how long to let the pens be immersed? A few minutes? Hours? Overnight?