I think the recipes for products like Selco and Selcon are proprietary and not available, but there are a LOT of recipes out there for enrichment purposes.
IME, it's more trouble than it's worth and I no longer do it, choosing to use powders I buy from Algamac and Brine Shrimp Direct that don't have the storage drawbacks that the emulsions do.
Here is the formula I used to use.
Enrichment Page One
Enrichment Page Two
It should be noted, that hobbyist set ups CANNOT duplicate commercial operations and that hatch of the newly hatched nauplii is spread over a wider time line so that getting to the Instar II stage which is necessary for them to feed, (Instar I incomplete digestive tract) is longer such that you need to wait until they are approximately a day old (after hatchout) before enrichment begins. If your operation is cool water like my 68°F then even two days could be necessary.
IME, for nauplii in Instar II stage, 12 hours gives excellent gut loading, but two 12 hour stages with new water and new enrichment makes them gut loaded but they have additional nutrition because by then the enrichment has started to assimilate into their bodies.
As the artemia go through the molts to adult, the time for gut loading decreases so that adults can be gut loaded in about 4 hours.