"
for anyone who drives, it apparently works very well to really clean car windscreens too!" ...........Is there anyone here who doesn't drive

- I believe that Sue doesn't have access to 'wheel's - but can't imagine there's anyone else here who doesn't have a set.
Coming back to the subject of wire wool - and Mikael's comments regarding the Riedel steel pearls - I've pinched the following data from the webb, which illustrates why steel/wire wool will leave marks on glass.
The relative hardness of some materials are: Diamond 10.0 - Steel 7.0 - Glass 5.5 - Tin 1.5
Fairly obvious really, I suppose, and I guess most people would know that steel is harder than glass. As already mentioned, wire wool does have its use - insofar as it will manually remove a fair amount of limescale quite quickly, and improve the clarity of the piece (especially when used with a carrier such as Brasso plus additives like aluminium or cerium oxide). As someone else commented about a year back......."then you just smear with a little silcone grease, and hey presto all blemishes are invisible) - sounds like a skin cream

Of course if you have wide access to the internal parts of the glass then in goes the flexible drive/cotton mops (hessian/leather or whatever) and no problem - BUT, then you have the problem that if the issue is not limescale, and instead is a glass surface that has been eaten into, its good night Vienna, and you are probably snookered.
I get the feeling that if the cloudiness appears as a noticeable 'whitish' colour, then you have limescale - otherwise is is a case of glass sickness.
Having tried just about everything under the sun, except a tumbler or hydrochloric, I suspect nothing works as effectively as a professional acid wash, but must admit if I cud work up the enthusiasm I wud like to try a tumbler - just that most of my problem pieces are problem shapes, and might not fit

Must admit Anne that I haven't tried Barkeeper's Friend - but have been disappointed by so many of the proprietory products that just didn't live up to expectations.
So, anyone know what an average cost of professional acid wash might be??