Read and rate the best solutions below by giving them a "thumbs up".
I use a denture tablet in water. Just fill the cup with water and add a denture tablet and let it sit for several hours. Then just pour the water out and wipe the cup with a paper towel or dishcloth.
By shirlee 
To get stove top grates clean, place in a large plastic bag or sealable container with some ammonia. Close up the the bag or container and wait several hours. The grates will be easy to clean. Remember to exercise safety precautions when using ammonia.
By redbudtx from Dallas, TX
Coffee cups stained with coffee? Make a thick paste with simple table salt and warm water and use a soft rag and wipe the coffee cup inside and out with the salt paste. Sparking new!
You can also use the salt paste for porcelain sinks in the bath and/or kitchen. It's so much less expensive than store bought products and works as well or better than most!
By MasterMom from Round Rock, TX
Give a "thumbs up" to the solution that worked the best! Do you have a better solution? Click here to share it!