Hey, look at the bright side, you might wet test it, and they all hold fluid evenly, lol, then you can come back here and tell everyone my asshole is sucking wind, and I guess I would deserve it.
Should be able to get cleaning solvent, or varsol at the parts store, kerosene.
If nec, I would just slap the repaired heads on, totally understandable, but you at least know that plug will likely foul, put another plug in carry on.
Done that to many vehicles too, including my own, lol
What were the old plugs like, are they around?
Good luck .