You should use brushes to clean oil ways, don't rely on a blast of air....
google twisted wire tube brushes
Get a wire coat hanger, cut & bend it to give one long straight piece of wire. Twist one end to form a hook that will fit into the oil galleries.
Cut some pieces of towelling, soak them in paraffin or brake & clutch cleaner and use the wire to pull the towelling pieces through the galleries.
Do this after washing out thoroughly, then wash again when the towelling comes out completely clean. Use several pieces of towelling and don't pull any single piece through more than twice. This is how a rifle is cleaned.
Finally blow through with compressed air.
Fit new gallery plugs using a bit of Loctite Bearing Seal.
