If you use the search function, type in "sticky steering wheel", you should get 54 threads where this has been discussed before. Solutions are anywhere from soaking in degreaser to putting into the dishwasher.
Rumor has it the old hard plastic wheels deteriorated, but the later somewhat softer wheels or at least mine cleaned up good. Its black 4 spoke wheel from a later Camaro from a scrapyard. It had been there for a while and was filthy. Ran it through the dishwasher a few times and scrubbed on it, but the thing that finally cleaned it was immersing it in purple power for a while and scrubbing periodically. When fresh, purple power will slowly dissolve you.
I've also put things like plastic dash bezels in it to remove everything down to the plastic.
Ran into a gal at a swap meet that refurbished steering wheels she would soak them in soapy water for a week or two and scrub on them a couple of times a day to get them clean. I done this with rubber parts off my car like the bump stops on the A-Arms they came out looking like new.
I know there are countless threads on this...but wanted to add something. You can clean a sticky steering wheel with many of the methods described in this thread and others. If the steering wheel is sticky because of oils from your hands, this works fine...but if you have one where the wheel is truly breaking down and "oozing" like I did, then it's good for a while but always comes back. I looked into the chemical makeup of the steering wheel and looked for a solution that would completely seal the wheel so the petroleum could not ooze as it breaks down. So I cleaned mine up really well, then sprayed about 10 coats of satin finish polyurethane (rattle can) on it. It looks great and it's been about a year and stickiness hasn't returned. Used Satin finish so it wasn't too shiny. It just looks like it always has a fresh coat of Armor All on it. FYI - mine is the rope style.