I use a brass dremil tool to get all the crud and stuff out of the cracks in the knobs.
Use a low speed and take your time.,.Wear safety glasses. It works for me.

I use hand soap and an old toothbrush to clean old knobs. Then, if the bakelite is not too gouged up, I use Novus #2 polish to bring up a nice mirror shine on the smooth parts. Sometimes there is powerful crud in the finger grooves that does not always come out at first. I then go over them again. They make a fibre brush for a dremel tool that I might try before I got more aggresive with a wire brush. Also polishes like Flitz or Simicrome or other metal polishes of the paste type can be tried on dull bakelite knobs if you don't have any Novus or plastic polish. Some have used toothpaste too.

I have had good results getting grunge out of deep recesses with a bit of COMET kitchen cleaner (Powder) and a toothbrush. Has "just" enough abrasives to do the job without scratching.

I learned this tip here. Use denture cleaning tablets. I put just enough hot water in a cup to cover the knobs by a half inch, then a tablet or two. When I take them out, I god over them with an old tooth brush, then rince them. It works very well. Then they can be polished.

Next time I may just try the fiber brush and dental powder,,that should work good.
Thanks for the tip

I use a Harbor Freight $20 Ultrasonic Cleaner that works very good.
Drop my knobs in the tank along with some cleaner and let it do its job.

Carl

A stitched (firm) cotton buffing wheel (anywhere from 4 to 8 inches in diameter) loaded with plastic cutting compound can also clean bakelite knobs very quickly and to a very high gloss. One needs to hang onto the knob very carefully though, as one time my wheel grabbed a knob and hurled it like a bullet through the basement window. My wheel is on the Shopsmith so I can adjust rotational speed as needed.

Have had the same experience with my buffing wheel. They can cause some damage. So here is what i do. Sacrifice a few old pots and cut the shaft off of them. Put the shaft in your variable speed drill and attach the knob to the other end. Put a little polishing compound on a rag and polish away. Wait till the compound has dried and use a tooth bush to clean any of it away. Coat of wax and you are done. Much safer this way.
Stan Ski

Wear rubber or vinyl gloves for this: Use a tooth brush and undiluted ammonia. The ammonia loves skin oils, coffee and tobacco residue. It only requires just enough to moisten the tooth brush, so the fumes don't pose much of a problem.

The surface of a bakelite knob, once abraded, will never be shiny again. Soaking in ammonia or brushing gently brushing with an old toothbrush and pumice can remove the grime. Then good old fashioned paste wax and a gentle buffing. Oft used knobs have to have this repleated once in a while.

More serious flaws will require grinding, sanding, brasso, etc..., and some kind of coating to restore lustre.

He he, sneaky trick, on now clean but dull knobs, Mop & Glo floor polish, works good on panels too. A learned skill as daubing around the polish while it is polymerizing can lead to an uneven shine... Once built up, can be buffed to deep shine like a floor...

I heat up some water to a boil with a couple packs of that stuff used in the dish washer and throw my knobs inside along with my wife's rings and everything comes out sqeaky clean and shiny.

Carlos

Ive found rather good results using cheap toothpaste, it usually has more grit. Using a dremmel tool with only a buffing wheel, it seems to get them rather good. Then a light jewelers rouge for final polishing. I tend to rub then down with boiled linseed oil afterwards, it seeps in and when wiped off, theyre shiny and new looking.

Okay, thats my 2 cents.

I find "Simple Green" works very well using a toothbrush. I let them dry, then buff them out on the drillpress> Carl.

Most of you guys are in too much of a hurry. I just throw all the knobs in a mason jar with hot water and baking soda, then let it sit for an hour while I do other things, then brush the knobs clean with a toothbrush. Works well on every type of knob.

I now use a simple/easy method I learned from a friend several years ago. I just spray them down real well with furniture polish (Pledge) and let them sit. If they have a lot of grime the Pledge softens it up and a soft toothbrush will remove the crude from cracks and crevices on the knob. As a bonus, as you wipe them off with a soft cloth they are already shined up.

out of all I like the baking soda. cold water should be better. hot or boiling might warp knobs

I bought a Harbor Freight 100 watt Ultra Sonic Cleaner and it works great on knobs. I used the cleaner they sell there too. Sure is a lot better than scrubbing over a sink for hours. Some knobs come out looking new. Your wife might even be happy with how it will clean her Jewerly

I gotta check out the untrasonic cleaner from Harbor Freight.

I bought a "Spinbrush" toothbrush a couple months ago. I liked the way it worked (on my teeth) but read where they were causing damage. I think from over aggressive use. I retired the spinbrush to cleaning radio parts, mostly knobs..it works excellent.

I have since bought a Sonic-care toothbrush (7X more $$)

On some crud, good ol' saliva, given a couple of minutes to do its digestive work, is a useful tool. And most of us have a ready supply at hand. And no, I wouldn't recommend popping the knob into your mouth.