A Spell to Break the Powers of a Spell

If you believe a spell has been cast against you, place a large Black candle
in a cauldron (or a Large Black Bowl). The candle must be tall enough to extend
a few inches above the cauldrons rim. Affix the candle to the bottom of the
cauldron with warmed beeswax or the drippings of another black candle so that
the candle will not tip over.

Fill the cauldron to the rim with fresh water, without wetting the candle's
wick. An inch or two of the candle should remain above the water. Deep breathe,
meditate, clear you mind, and light the candle. Visualize the suspected spell's
power as residing within the candle's flame. Sit in quiet contemplation of the
candle and visualize the power flowing and growing with the candle's flame
(yes, the power against you). As the candle burns down, its flame will
eventually sputter and go out as it contacts the water. As soon as the flame
has been extinguished by the water. the spell will be dispersed.

Break your visualization of the spell's power: see it explode into dust, becoming impotent.
Pour the water into a hole in the ground, a lake or stream.
Bury the candle.
It is done.

~Taken from "Wicca a Guide for the Solitary Practitioner", by Scott Cunningham.