Eutectic KNO3-NaNO3-Mannitol propellant was made with the same method described here. Mannitol has the lowest solubility in water from all sugar alcohols, therefore it is very less hygroscopic. The cured propellant has a density like ceramic. It deflagrates similar fast as using sorbitol but whitout bright white flame and a lot of white smoke is generated.
Cured propellant chunks:
As the state of matter of the propellant during manufacturing is liquid, carbon fiber, cellulose fiber etc. could be inserted to reinforce the propellant.