Ash at Oil City answers pickup questions:

OilCityPickups

Well you need a double boiler and some wax - and a way of keeping the whole thing at about 65 degrees C, then with the cover on you give a quick pot ... the secret is that when the cold pickup goes into the wax it will turn white as the wax solidifies - as soon as the white has disappeared - pull the pickup and set it upside-down on aluminium foil creating a slight 'dish' around the pickup. This way the wax drains to the inside of the cover where it's needed to stop drumming ... but doesn't all drain away outside the pickup. When the wax has solidified to 'rubbery' in the pool at the top of the pickup you can just peel away any that remains and polish the top of the pickup (perhaps using a little splash of white spirit. 
Job done

PS a heavy pot is anything up to 'all day' in the sauce.