Wright’s is the brand of cooktop cleaner I use, and as far as I recall, the price is actually SLIGHTLY less than the silver cleaner. Plus, the silver cleaner is a paste*, and it’s thick and messy, whereas the cooktop cleaner is a liquid and is easier to rinse off. Though Rilchiam didn’t say she was cleaning silver, she did ask about cleaning stuff she might already have on hand, rather than buying something specific for jewelry, so I thought I’d throw that out there for anyone who might find it useful.
(*I might be wrong about this brand being a paste, but the silver cleaner I have IS a paste, and I’m pretty sure it’s Wright’s.)
That might be due to the age of the rhinestones. The silver or foil backing on the stones is the source of the sparkle, and if it has darkened or started to flake off, there’s only so much you’re going to be able to gain through cleaning.