HI heres a mix that works.but dont over do it.it come from another very nice member in here quack quack just kiding duckie.but you are a vey nice person.this is duckies recipe.
Poison Ivy Vegetation Killer
1 cup salt
8 drops liquid detergent
1 gallon vinegar

Combine the salt and vinegar in a pan and heat to dissolve the salt. Cool the vinegar, add the detergent, and pour some of the liquid into a large spray bottle. Spray the vegetation. (You can also just pour the mixture onto the weeds.) Refill the spray bottle as necessary. Note that this formula will kill all the vegetation, so make sure that you are only spraying the plants you want to kill. If you need to use a lot of this spray, avoid spraying it near wells, as the salt can leach into your water supply.

hope this helps your friend in gardening DIGGER