Q.How to make my sick hibiscus healthy and blooming again
My Hibiscus has sticky leaves. The leaves are lifeless and becoming light green. I have sprayed horticultural soap, and whilst doing so, a lot of white tiny stuff flew around. It is still indoors. Can I take it outdoors today?
It is almost 10 years old it and is not giving as much flowers as it used to but the plant had lots of healthy green strong foliage. I have fertilized it with Shultz water soluble 10-15-10 fertilizer today.
Please help me to save my plant.

You should be in warm enough temperatures to put outdoors.
The sticky leaves are most likely honeydew, which is a byproduct of insects excretion of sucking insects.
A fertilizer should be balanced, 10-10-10 for example, but don't panic for using the type you did.
Allow the horticultural soap to work and keep an eye out for any signs of insects and damage. Neem Oil is a good choice.
Late summer is a good time to lightly prune your plant and help rejuvenate it.
Here are some links to help you refresh you on the care requirements.
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-sticky-leaves.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/how-to-care-for-hibiscus-plants.htm
https://www.gardeningknowhow.com/ornamental/flowers/hibiscus/hibiscus-fertilizing.htm