With warmer days on the way, it's a good time to clean patio slabs, garden furniture and your barbecue ahead of spring. A few simple household staples, including white vinegar and washing-up liquid, can help lift dirt, algae and winter grime. Jump to: 1. How to freshen up your patio slabs 2. How to clean your garden furniture 3. How to scrub up your barbecue 4.