Yes I do prefer organic, but do use weedkillers and insecticides when absolutely necessary. You say the patch you've dug over was lawn, therefore presumably you don't have brambles or docks in it. I presume the only perennial weeds you need to worry about are daisies and dandelions. If you are not planning to plant or sow anything till next spring I would suggest covering thr whole patch with old carpat or weed suppressant membrane (pr sturdy bits of cardboard) and leaving it alone till spring. Then you can dig it over again and start sowing. When you dig it in spring try to remove any dandelion and daisy roots, then you shouuld be off to a flying start. Good luck!