Some time ago Mr. Vorobyov invented a developer for silver-halide holograms that does not contain any rhodanides. It is ideal for both beginning and advanced holography.
The original Russian article is here: http://www.holography.ru/tech8rus.htm
Original formula:
Metol = 2 g
Sodium Sulphite (anhydrous) = 25 g
Hydroquinone = 5 g
Borax B[sub]4[/sub]H[sub]4[/sub]Na[sub]2[/sub]O[sub]7[/sub] = 2 g
Sodium Thiosulfate (photographic fixer) = 6 g
Water = 1000 ml
Here sodium thiosulfate replaces rhodanide. It dissolves AgBr so that the process is the physical one and not the chemical one.
Simplified formula - made from Kodak D-76, ideal for beginners (image is slightly worse but still works):
Take Metol and Hydroquinone mix from two ready-made 0.5l D-76 packages (2x[1 g + 2.5 g]). Take Sodium Sulphite and Borax mix from one package (1x[50 g + 1 g]). Add 6 g (one teaspoon) neutral fixer (Sodium Thiosulfate). This will result in following:
Metol = 2 g
Sodium Sulphite (anhydrous) = 50 g
Hydroquinone = 5 g
Borax B[sub]4[/sub]H[sub]4[/sub]Na[sub]2[/sub]O[sub]7[/sub] = 1 g
Sodium Thiosulfate (photographic fixer) = 6 g
Water = 1000 ml
DIssolve Metol and Hydroquinone first in some warm (40-45 centigrades) water, then add everything else, add water to 1000 ml and filter the solution.
The resultiong solution should be mixed with water 1:4 before use. Develop around 10 minutes at 18 centigrades.