Existing fence, want to add electric fence

[CrazyTalk]

I make my own.

1 gallon of white vinegar, 1/2 cup of dawn dish soap,2 cups of epsom salt. Mix..put in pump sprayer. Apply on dry sunny day.

This stuff is significantly less effective than roundup (it doesn't actually kill plants - it just burns the leaves), and significantly more dangerous - aerosolized vinegar is a severe respiratory irritant. It's also more expensive than roundup - there's literally no reason to use it.

And no Fenwickchick, roundup is not linked to breast cancer.