What can I use to clean my chrome towling rail?

I'd start with something like Dow Bathroom cleaner. If the water stains turn out to be minerals, vinegar should do it. It might take time to dissolve, but shouldn't take much rubbing.

Roger's right. A bit of vinegar in a little warm water should dissolve any minerals on the chrome.
Here's another tip: As soon as the bar dries and you see any water spots, just take a dry washcloth and buff them off.

Half of the time water spots aren't minerals, they are soap scum. Wetting them just moves the greasy soap around, buff them off and they are gone.

If you ever want to remove the soap scum from a shower wall or glass door, get 0000 steel wool (that's the finest grade) and use it DRY to buff off the soap.
(It scares everybody the first time I suggest this)
But what happens is the pad gets filled up very quickly with what looks, and is, soap powder.
Use circular motions and just keep turning the pad over until it won't pick up any more, then get another dry pad and keep going until all the scum is gone.

You can use 0000 steel wool to clean the spots off of mirrors and chrome works too.

I can't emphasize enough that the wall and the pads have to be dry for this to really work.

You can just throw the used pads away or, if you are really thrifty, take them into the kitchen and use them just like you would any other soap-filled steel wool pad.

extra credit: you can buff off the cigarette smoke film from brass lamps using the same drypad method.
Joe(0000 no scratches)Nation

white vinegar, baking soda, salt, etc seem to be forgotten cleaning products nowadays.

eco friendly, cheap and abundant.

PS: I hate chrome and stainless steel when used decoratively.

yeah, the guy that bought my porsche wanted to put some chrome on some engine parts, I told him I would hunt him down and kill him. the only chrome left in my house is the water faucets.

Hydrochloric acid, often sold as muriatic acid in construction supply companies will take that chrome right off.

You're welcome.

can't do that, Lady Diane picked out the faucets.

I will make a point of complimenting the faucets next time I see them.