You can use a baking soda and water paste. rub the past on the Silicone and let sit for a few hours. Then rub off with a dish rag and hot water. This worked great for me!
I have RA also, and have found a lot of the products to be very easy to use. I LOVE the crinkle cutter, and use it to cut blocks of cheese in no time flat! The easy opener is wonderful, as well as the garlic press. I have tried the can opener, and can see how that would be arthritis friendly...