A water-dampened pipe cleaner to expand the RTV works better. RTV sets up by exposure to moisture.

This is exactly correct!!! RTV must have humidity to cure.

Mopar Mitch "Road racers and autocrossers go in deeper and come out harder!"... and rain never stops us from having fun with our cars... in fact, it makes us better drivers! Check out MOPAR ACTION MAGAZINE, August 2006 issue for feature article and specs on my autocross T/A!