I never would have thought that salt or vinegar would kill weeds.
To be fair - although it is true that vinegar is a natural herbicide and it is something that has been used by organic gardeners and farmers for decades and it does to some degree work.
It is not 5% household white vinegar dilated with water that is used - as although that may - if you are lucky burn the tops of some young non established weeds - especially if the sun is shining on them - they will be back in next to no time - simply because that solution - its just not strong enough to kill even the weakest of weeds.
Which is why - if wishing to use vinegar to kill weeds - it would be way better - not to use the household vinegar you put on your chips or salad - but use the much stronger solution that organic gardeners generally use - which is
a gallon of undiluted 20% horticultural grade vinegar, mixed with 1-2 ozs of horticultural grade orange oil and a squirt of dish-washing detergent
which when applied in full sunlight on a hot day - will burn back some weed species quite quickly with one application - but for more resistant weeds - repeated applications will be needed in order to get the weeds to fully die back.
I would also just add - that although vinegar is generally thought of as natural and quite safe - as vinegar contains acetic acid - which is a chemical - yes a chemical - with well-known herbicidal properties - it should be treated and handled in just the same way as any other chemical - meaning - always store in a safe place, wear gloves and goggles when applying - as well as - keep pets, young children and those with respiratory problems - well away from any areas that have been treated - until all residue on foliage has fully dried.
Salt however is something that should be used with extreme caution in the garden - especially as - not only does salt raise soil salinity - thereby stopping plants from absorbing necessary nutrients from the soil - but more importantly as salt leaches into the ground and can stay in the soil for many, many years - preventing any kind of vegetative growth - its highly unlikely that anything will grow in a salt treated spot for a seriously long time.
Its also worth bearing in mind - that as salt doesn’t always stay where its been put or discriminate between weeds and other plants - as it can be washed off into vegetable patches, flower beds or lawns - it could very easily - especially during periods of heavy rain - wipe out huge swaths of plants that you want to keep.