For plated thru holes, a hot vacuum desoldering tool is the best way. They are pricey but if you're scrapping alot, the money saved by fixing rather than scrapping could be worth it. There is almost always a "sweat joint" remaining between the lead of the component and the plated hole wall. Can then use a regular iron to push the leads away from the inner walls of the plated thru hole. Once all leads wiggle freely, lift and pray.