When re-installing the plugs, a couple wraps of regular teflon tape will work just fine, then snug the plug. The sealer used by Ford on these just makes installation easier on the assembly line.
2004 Freestar Limited 4.2 V6 w/Water Injection & Iridium plugs
2010 Lincoln MKZ AWD (Vacationing in Arizona)
2007 Focus SE (Just bought 9/29/2012 @ 59K miles)
1979 Gilson 32" 10HP Snowblower
2007 Generac 17.5Kw Generator w/33HP Twin-Cylinder engine
Farmhand 3-Cylinder air compressor
AMSOIL Lubricants and Filters in everything
"Have a good day, and a better one tomorrow"