It was on their 5/10/03 newsletter – here’s a copy/paste from it…
FRUGAL HOME / GARDENING
POISON IVY/OAK/SUMAC IN YOUR YARD?
INVASIVE PLANTS TAKING OVER?
Here’s a simple recipe that will kill vegetation without chemicals. Keep in
mind that if the poison plant is not in anybody’s way, it’s a great plant
that feeds birds with its berries. Angora and Spanish goats love it too. If
you absolutely must kill it or something else, here’s a non-toxic recipe:
Place 1 gallon of vinegar in a large pot and add 1 cup of salt. Heat till
the salt dissolves. Cool and add 8 drops of liquid dish detergent. Put in
spray bottle or pour on the poison ivy. This formula is not
poison-specific. It will kill any vegetation you pour it on. Be careful
where you spray or pour.