How much time do you have before adding fish to your tank? Household ammonia can produce a huge bioload - cheap too for your size of tank. But it would probably take weeks if you don't have any seeded filter media to start with. I've used Seachem Stability many times - but you need fish in the tank and daily dosing and monitoring.
Stability works if you use for 7 days in a row. They have one kind of bacteria that survives in a bottle. I was told the same thing it dies in a bottle. But I've used it and I've sent home to customers with brand new tanks and told them to add for 7 days and they succeed. Those are new fish keepers . Of course I tell them stock with a few fish and very little food at first and gradually add their fish