if you only need a month strip some elctrical wire and wrap the strands around the plug thread. mix some araldite or similar epoxy resin coat the plug threads and screw it in. leave overnight and it ought to be good 'til the new engine's done. spray some carb or brake cleaner on the heads thread and blow it dry before gluing the plug in.
it's a bodge but it usually works, as long as you don't want to change plugs again on that head. good luck.