Tashlich (Tashlich is the ceremony performed on the first day of Rosh Hashanah, the Jewish New Year, when bread is cast into a stream or river to signify the casting-off of the errors of the dying year.)
Tie them in a sack, with knots as tight as the knots in your stomach: tie the knots double, lest what's inside is the Houdini of your private demon-closet, and may escape. Weight them with stones, carry them to the shores of some convenient stream of living waters. Cast them as far as you can (pray for them if it pleases you): but let them drown.
I'm sorry if you're squeamish, and yes, killing is a sin, but it's a war, after all: and if you get queasy at the thought of what's in the bag squirming, choking for air, think what they would do to you if they got loose, what they maybe did to you already, or tried. Consider it a mercy-killing, consider yourself prepaid on the Five Stages of Grief, and this casting-off a celebration.