The polishing oxides include aluminum, cerium, tin and others.  They only remove elements that are attached to the glass, such as a lime deposit, mineralization, rust stain, food stain, etc. - not etching and/or scratching.  Since polishing oxides are softer than glass, they will not cut away at the glass, thus they do not effect embossing, but do give the glass a "spit clean" shine.  These are the same materials used to polish eyeglass lenses.         

Aluminum oxide is on the hard side of the polishing world, and is inexpensive. On a scale from 1 to 10 with a 10 being the hardness of glass, it would be about an 8.  It is a good all-purpose polish and it is my favorite because of its cost and ease of cleanup.  Sometimes it is too hard for soft glass (such as a pre-1850 glass and some amber glass.

Tin oxide is also a hard polish (around a 9).  It is the most effective polish to remove light frost from cutting (with 1200 grit silicon carbide) on extremely hard glass (such as cobalt, dark green, black, crystal and clear glass made after 1900).  

Cerium oxide is a soft polish (around a 5).  It works best on extremely soft glass (such as pre-1850 glass and amber).  It will also give a better shine on the glass. The disadvantages of cerium is that it takes a little longer to polish and it is harder to rinse off the glass.  It cannot effectively remove frost from cutting on medium to hard glass.

The cutting oxides remove etching and scratching and include silicon carbide.  The cutting oxides are available in various grit sizes depending on the severity of the etching and/or scratching, and the properties of the piece itself.  The cutting oxides can remove etching and/or scratching in about 5 days, or the entire embossing within 12 hours, depending on the grit used.  The cutting oxides are better left unused until you become familiar with your machine and the removing capabilities of the polishing compounds.  At this point, you will have a better sense of what types of "sickness" will require cutting oxides.

1200 Grit Silicon Carbide is an extremely fine grit oxide.  Since it is harder than glass, it is an effective cutter that is used to remove light-scratching and etching from the glass.  It is safe to use around embossing.  Depending on the hardness of the glass, it will generally take around two weeks on the machine before the embossing will start to show a rounded effect on the sides.  The 1200 will generally (except on very hard glass) leave a light frost on the glass which will require a second turning using polish.

600 Grit Silicon Carbide is not to be used around embossing (it will remove embossing from a bottle in as little as 24 hours).  It is an extremely fast cutter that is used when the inside of a bottle (or outside of an unembossed bottle) is heavily etched.  600 will leave a heavy frost which will require a second turning with 1200, followed by a third turning using polish.

Loading and unloading instructions are available, which include the recommended amounts of oxides to use for different item sizes.  An example is 3 teaspoons for a pint fruit jar in a 5-inch canister.  I recommend that you start with a pound of oxide for every canister you will turn at the same time.  Each pound should clean 30 to 35 tumblings.  As you clean your items, you will find which oxide works best for you and the objects you are cleaning.

NOTE: Oxides come in many different grade purities and grit sizes that can greatly alter the way they will work on glass.  The supplied information is based upon the specific oxides that I sell.