For very fine sanding and certain surface repairs (like water spots) some fine metal wools and pumice stone or rotten stone are useful.
First let’s explore the uses of steel wool and some brass and bronze wools. All metal wools are graded just like sandpapers. Here is a useful explanation of how these grades would be used by you.
Grade 1 The coarsest grade used in wood finishes. Good to use with varnish remover to clean prior finished surfaces.
Grade 0 Used with paint and varnish removers. This grade helps to rub off spots in the finish.
Grade 00 Is often used after sanding to prepare wood for finishing
Grade 000 Can be used to remove water spots from wood if used with oil or furniture polish
Grade 0000 This is the grade I often use for a final buffing tool.
Now, about the drawbacks of using steel wool. (I often use it.) The wool will become very clogged with oils and wood and must be discarded often. Also, a real problem is that some of the wool will rub off and be imbedded in cracks and crevasses. Over a period of time this wool will rust and damage the surfaces of your sculpture. I use a small magnet to try to remove this residue. With care, steel wool will provide a wonderfully smooth finish.
Now, the facts about the abrasive minerals we could use in our fine finishing.
Pumice – White or Gray. Its a mineral by-product of eruptive material from volcanic action. This mineral ash is ground to a very find finish and can be obtained in various grades. F to FFF, with F being the coarsest. I use FFF grade. I dip a small square of soft fabric or fine Brassotex in mineral oil, dip the oiled material into pumice or rottenstone and rub for a fine finish. It also does a good job on stain removal. Pumice is coarser than rottenstone.
Rottenstone is a residual product of the decay of Silico-Aluminous limestone. This residue stone is found as a soft friable earthy mass which forms a cheap and highly satisfactory polishing material. Rottenstone has no grading. Use it in the same way as you would pumice or steel wool. Rottenstone is the finest grit so it is a great finishing product. Start with rottenstone if you feel you are at a finish stage but if it proves to be too fine then start with steel wool or pumice. For final finishes and buffing, all the above products mixed with oil do a great job! Also all are good for stain removal.
Varnish-like finishes are acceptable on bases only, not on LuRon sculptures. I have seen some WOW bases beautifully finished with this technique, but be careful not to allow a beautifully finished base to detract from your sculpture.