question why not just do 2 part paper mache or
a 2 part plaster casting for a real hand to make mold ? almost any hand position can be done in a 2 or 3 part casting and skip the hot wax? (if you want a wax hand to do modifications on read bottom part about how i did face for ideas.)
i can see the wax might be faster than plaster when making a hand mold but the detail of the hand is inside of the wax not on the out side.(a glove filled with clay as it drys can be shaped into any position really would give about the same result as the outside of wax hand).
anyway back in high school art class(1970's) we made full body parts castings to make full personal clay likenesses when asembled all together and flesh color painted, the thing is even... with the vasiline on body parts the natural skin creasses / wrinkles and some arm hair patterns will show up in the plaster castings giving a very real look to cast item. it was fun making all the arms legs body etc. (no naked kids we had to wear tight one piece swim suits)
but when it came to doing the face i cheated,,while other kids had straws up the nose and mouth and laid on the floor for plaster on face- per teachers directions (you do the back of head in a swim skullcap cast first, put head in that cast then divider then put wet plaster on face yes everything gets vasiline thats getting cast)
i went home and took kitchen tinfoil - pressed that to my face as sooth as posible, then stuck my (fully tinfolded) face in wet sand indent/hole in a plastic box (use elmores glue in the water will help hold shapes in sand) i wiggled my head, hard and deep then leaving foil in sand, took my face out carefully(this all took less then a min just held my breath). then i drizzeled clay slip into foil to coat and repeated over and over till i had a good shell of my face (90 % accurate). yes it had flaws from the foil creases but all i had to do was repair and smooth by hand to make a fair likeness bust of my head. now i had a good replica of my head. i had no problem making a plaster head cast .. no straws no freaking out under plaster for me
yes i got A's in art classes due to my creative engineering - when really it usually was just short cuts ( me lazy) or necessary personal adjustments to a technique
to complete a class project. its amazing that there wasnt straw failers or kids beathing in wet plaster. but classes after that the teacher had kids do head busts by hand 1st. (no i didnt tell her how i made head bust, guess she thought i made it all by free hand sculpting eep i am not that good, but its the end product that counts ..right?)