Mine have been sticky for years, but I always forget to research the solution. But recently I had the same condition occur with a spatula in the kitchen. It's the OXO brand and I wrote them because I have a number of their kitchen tools that share the rubbery grips. They replaced the spatula, but had no idea what the condition or solution was. Hard to believe, eh?
So, tonight I looked up this thread. Thanks guys, for the easy answers. Tomorrow I'll try the alcohol on the knobs and handle.
Will report back to the thread.