Hi - I had a complete hysterectomy about 2 years ago. Like you, and another women who replied, I wanted to do it alone without hrt.
I am by no means an herbal/vitamin nut so I went and learned about what works and why etc. I found out that with regard to herbal supplements the quality of the product and the dose are key to making it work. (i also found out many are medically recommend and some of the stuff is just hooey).
With that said I was ready to try a black cohosh supplement that was around a long time called remifemin. When I went to buy it I was told by the herablist in the store that it is a quality product but she has seen more women have success with a brand called oona. So after talking to her more I followed her advice and after about 5 weeks of taking it I slept like a baby and had no more hot flashes. I was blown away with the results. Look, I do not want to sound like a commercial but I was shocked and felt that I had to tell others that were going through this hell. I hope this helps. Good luck!
Tintures a good also, but a pain to deal with.