Sounds like it's a compost tea. I don't think it would hurt new seedlings, I personally would wait til they have a couple nodes, but that is just me. Follow these directions, should be good. The tea will brew for 24 hours so it'll be room temp.

From the interwebs:

The FOLIAR PACK was designed as a 100% safe, non-chemical spray or drench made up of naturally occurring microbes that may help plants deal with environmental stress. Protect your plants and your investment.
Stop using harsh chemicals to treat your problems and start using the FOLIAR PACK!
OG BioBrew
OGBIOWAR recommends applying the ROOT and FOLIAR packs via BIO BREW for optimum results! Here is how:
1) Fill a 5-gallon bucket with 4 gallons of NON CHLORINATED water.
2) Add 100 ml of regular unsulphured blackstrap molasses.
3) Adjust pH between 6.5-7.0
4) For soil or hydro add 4 tablespoons each of the ROOT and FOLIAR PACK.
5) Fill a cheap stocking with 1-2 cups of high-quality earthworm castings. Tie this off and let it float in the solution like a tea bag.
6) Bubble with a 6” air stone disc and air pump rated at 60 LPM or more, for 2-48 hours. OGBIOWAR likes a 24-hour BIO BREW.
7) Turn off air pump, let the tea settle for approximately 10 minutes, and take/pour brew off the top to avoid sediment.
8) Rinse out sediment in the bucket for future batches. Clean tubing, air stone, and bucket thoroughly in between brews.
Add any nutrients or additives and pH BEFORE adding the brew to your normal regimen. The day after a reservoir change (once every 7-10 days) is a good time to add tea.
DOSAGE:
Add 50mL of tea to every gallon of stock solution for any recirculating system. Change solution weekly! Dilute one gallon of tea to 9 gallons of stock solution for nonrecirculating systems.
Soak new cuttings in full concentrate tea for 10 minutes prior to placing the cutting. If using a cloning machine, add to the reservoir at the rate of 50mL per gallon.
Foliar feed with this tea once every 7-10 days at full concentrate. Let the tea settle well, or strain to avoid clogging the sprayer.
Pour tea directly into crown and foliar as well.
Can be used up to harvest/flush at users discretion.