Collectors of obscure books on clothing (yes RJ, I am thinking of you) may wish to consider Franco Biancacci's L'ABITO DELLE MANI viaggio nel mondo della guanteris in forma di racconto which translates loosely into English as GLOVED HANDS a journey into glove making should you be able to locate a copy. A multilingual book with 86 pages in Italian and a condensed 21 page section in English, amidst its advice it offers the only recommendations for cleaning gloves that I have ever seen (assuming, that is, that your grocer can recommend a suitable detergent). I quote:
1: first of all, you can not use any detergent; it is a product that removes stains and cleans thoroughly but in a very delicate way, ask the grocer.
2: in a bowl put one or two liters of warm water and add two cupfuls of detergent and a tablespoon of vinegar useful to fix the color. Dip now the gloves in water, however taking care not to put together light and dark gloves. Once this is done, leave to soak for half an hour without touching them.
3: at this point, wear gloves and wipe the hands as if you were washing them. Now remove the gloves and rinse thoroughly under warm running water.
4: dry gloves; wrapping them in a towel (maybe old, as they will release some color) and then expose them to the air, keeping them away from sources of heat and direct sunlight.
5: before they are completely dry, insert them gently; they will resume the original shape.
6: and if you could not be able in making back brand new your gloves, well, don't worry, you can always choose new ones among the countless, beautiful products of the best Italian craftsmanship.