i had a lovely garden but im not able now to look after it so i decided to decant the eartgh out all beds and cover with black membrane and then chip over it also have monoblocked and paved all other areas my thinking being that all i have to do is get someone in twice a year to power wash and sweep sand into monoblocks but i have lots of weeds and moss growing inbetween were sand has been washed out or blown away so i was told by a mature gardener that if i swept salt into crevices instead of sand that would control weeds londer advise please i do not intend to use garden again for growing
Yes, salt will kill the vegetation and prevent emergence for a very long time. However, the amount of salt necessary to do that is probably more than you would expect. I suppose that if you kept adding a little salt and sand after a while you would reach the point where it killed the vegetation. Then the results last for a long time, and you won't need to add salt for years.
Using polymeric sand between the pavers will also be helpful for controlling growth.