Celluloid is a highly flammable cellulose nitrate-based plastic. A typical formulation of celluloid contain 70 to 80 parts cellulose nitrate, nitrated to 11% nitrogen, 30 parts camphor, 0 to 14 parts dye, 1 to 5 parts ethyl alcohol, plus stabilizers and other agents to increase stability and reduce flammability. Celluloid is still common used in table tennis balls.
I had a few table tennis balls at home, so I cut one in half and took a whiff. I smelled camphor . I cut 3 balls in small pieces and desolved them in 50ml acetone, stirring the solution from time to time. It takes around 2 hours till the celluloid is completely disolved. I mixed then 5g of the thick celluloid solution with a prepared fine powdered mixture of 8.5g KClO3, 1.5g hexamine and 1g phenolphthalein and formed a snake on coated baking paper. The picture below shows the dried propellant and the celluloid solution (it is yellow because the table tennis balls were colored yellow):