To clean antique diamond jewelry you can presoak or rinse the jewelry to remove any losse dirt. Then you can use a cleaning solution and a gentle brush to remove any remaining particles.
The best way to clean a brown diamond is scrub it with a soft bristle tooth brush and use mild ammonia or commercial jewelry cleaner. You can find commercial jewelry cleaning solutions online at Amazon and Northern Tool.
Oxy Clean may be OK to clean just the diamond, but I wouldn't use it on a piece of jewelry. A home cleaning solution that is used in many jewelry stores is Mr. Clean and water with a small amount of ammonia. I will add a resource link to how to do this.
No, using toothpaste to clean jewelry will not hurt the jewelry. It helps polish and restore shine. It is a very good method of cleaning jewelry and a lot of people do it.
Like any other fine jewelry, clean Breil jewelry by using commercially available jewelry cleaners or there are a variety of options in your pantry and cleaning closet that will work as well. Ammonia diluted in warm water helps clean diamond jewelry. Undiluted white vinegar works for gold and other gemstones. For soft gemstones like turquoise and pearl, soap and water works well.
Get a soft, silky cloth (material) and rub it smoothly. Make sure it's dry.
The Swarovski pendant is a delicate piece of jewelry. The best way to clean this item is to bring it to a jewelry company. They have the necessary tools and skills to clean the item without damaging it.
Vinegar.
You can clean an antique copper faucet. However, you may not want to. If you clean the piece it could lose its patina which takes away from its value. If you do clean it, use soap and water and be gentle.
use warm soapy water and gently clean with a toothbrush.
I haven't seen vinegar clean jewelry but I saw my girlfriend clean my tarnished earrings with toothpaste. I was amazed.
You can clean hardwood floors without damaging it by first cleaning it like you would clean on tiles. Sweep up the floor for trash and then use a bucket and mop it clean and dry.
You did not state what the sculpture was made from. This would determine how you clean it.