If you are using hot wax as the wax resist, some of these suggestions will help:
1. As you suggested, you can fire the work again in the next bisque fire.
2. If the drip is minor, you can scrape the extra surface wax off and hold a
lighter or match under it to melt the wax out of the location of the drip.
3. You can scrape as much of the wax drip off as will come with a knife and
then take lighter fluid and lightly brush it over the drip and scrubb at the
wax to desolve it. (This takes a while.)
4. You can also use sand paper to remove some of the wax with the sanded
bisque surface. (Be sure to scrape the thick wax drip off before trying to
sand it....or you will simply smear the wax into a wider area with the sand
5. If the drip is minor, scoop off some thicker glaze from the side of the
glaze container and smear it over the drip. There is not enough surface
tension on the thick glaze so it will hold to the wall of the pot or
sculpture if the drip is not over a large area. I usually scrape and sand
the area first to be sure the thick glaze has a bit of a rough surface and
less wax under it.
These are old potter's tricks and you may not want to resort to the match or
the lighter fluid method in a class setting with the younger kids.
Good luck, Hope this helps.
Bob "the old potter"