Sorry to bring this thread back. I ordered my glyoxal from photographers formulary. However, you can use formalin, which is sold at aquarium supply stores in place of glyoxal.
combine 25ml of formalin to 1000mls of distilled water (outdoors) and submerge your paper coated with (plain) gelatin for a minute or two then hang to dry outdoors for at least a day. Formalin contains formaldehyde which is flammable and poisonous. Wear nitrate gloves, and definitely work out doors.
Glyoxal is my preference because it is slightly easier to work with. The jurys still out if it is less dangerous, so I take every precaution.