The egg mass is made up of around 10,000 eggs embedded in a matrix. I the eggs are fertile and the mother takes good care of them, they will take about 2 weeks to hatch. At that point, they will become planktonic, enter the water column and be sucked up by your filtration system, ground up by your pump, eaten by your corals, or cannibalized by one another. At any rate, after a couple of days, any that remain will starve to death. There really is nothing you can do to rear them. O. scyllarus young to my knowledged have never been reared to postlarval settlement.
If the eggs are sterile, the female usually eats them in a couple of days. Females can store sperm for a couple of months, but not across a molt. If she has molted since you got her and has not mated, the eggs will be unfertilized.
Roy