What do you use that both kills weeds and is safe for dogs? Our yards here are all or mostly rock (required), so it isn't an issue of lawn or garden care. See photo below - I don't have a choice on rock size. See photo.
I boil white vinegar in an extra-large Pyrex measuring cup, then pour directly on the weeds. Seems to do the trick. It might work without boiling, but that was the advice I was given, so I always do it that way!