Recommend a Cat-Safe weedkiller?

[Ha3el]

Thought this may be the best place to ask as what I can use which will not harm cats.. Badly need to weedkill the back garden which is out of control, but while our own cats can be kept indoors, many neighbours cats frequent our garden and the last thing I want is one to come to harm.

 

Most weedkillers say keep pets away until the product dries, but obviously I have no control other other peoples cats. I looked online for pet safe remedies and a site said to use things like boiling water, salt or clove oil. however on checking both salt and clove oil are actually toxic to cats so that seems pretty poor advice! Would be grateful to hear from anyone with a bit more expertise as to what is actually safe for cats.. there is the boiling water but garden is so thick with overgrown weeds i'd be a little worried about scolding anything hiding in there if i start pouring the kettle out