There is a type of plug that looks like a patch with a stem. They take the tire off the rim and put the stem through the hole and seal the patch down with glue. Then the excess is trimmed off the outside and the tire remounted. This is a better fix. Stabbing a tire with that sticky string IMHO should be considered a temporary repair and the procedure is outlawed in most European countries. The tire heats up quite a bit when driving on the highway and can cause the plug to fail leading to a blow out. Thats the last thing you want at 70 MPH. My advice, patch it correctly or replace the tire. Good luck.