I am not sure about hibiscus cuttings but many woody plants root fine so let me give you some general guidelines. It is worth the effort, you haven't much too loose but good experience to gain.

Take cuttings from young tender shoots, they will root easier than old hardened cuttings. You need to remove any leaves that are along the stem, where the roots will develop, leaving the top most leaves.
Dip the stem into the rooting powder. Be careful not to use too much. Some studies have reported that too much rooting hormone prevents rooting. Roots will develop at the 'nodes' where leaves used to be. Place your cutting in moist sterile planting medium, such as Vermiculite or Perilite. Form a little hole first into the medium with a pencil or something like that. Don't just push the cutting in. Gently push the medium around your cutting.

Cover the pot and cutting with a plastic bag and secure to maintain constant humidity. To keep the plastic off your cutting, fashion support from wire (coat hanger?). Uncover the container every day for about 1 hour to prevent mildew. Keep in a bright spot but not in direct sunlight for at least a month, maybe more depending on root development.

After you have roots developing, transplant into a pot of potting soil. Baby it along until the roots are strong and filling the pot. Now you can put it into your garden, it will be strong enough.

Best Wishes, Diane