If one is only willing to try 1 thing and it isn't working, the difficulty level & results are unlikely to change. I love rooting things in water because I'm good @ things that require me to ignore something for weeks at a time.
Woody entities generally are most likely to take root at the semi-hardwood spot, or the fresh green growth. If your cuts are down into already woody material, I would be less hopeful for success, though Hibiscus is not a genus with which I've done much in regard to propagation. The principles are fairly universal.
I usually let a significant amount of roots form before grounding. To plant, dig a hole, hold the plant with 1 hand and push dirt around the roots and gently firm it just enough so the plant is secure, then water thoroughly, at least every-other day for the first couple of weeks, gradually increasing the interval to hopefully weekly watering, but water as often as needed until your entity is established to the point of being self-sufficient, except during long intervals of no rain.
Putting a lawn chair or little table or some other type of temporary shade over a newly grounded entity can help give it some time to acclimate w/o too much baking. Shading like that can help a new planting regardless of its' origin.
You could try ground layering to the actual ground, or to an adjacent pot. Or air layering if you want to get fancy.
