[Dave at Pelican Parts]

Well, that's pretty darned annoying.

You have four alternatives that I can see, none of them particularly appealing.

1- Clean the goop off as best as humanly possible and then re-goop.
2- Pull the plugs and tap for pipe plugs, being as careful as possible to get all of the chips. (E.g., grease on the tap, pull it out frequently to wipe off grease and chips, etc.)
3- Pull the plugs, press in new plugs.
4- Tear the engine down, tap for pipe plugs as part of the rebuild.

--DD