"however prop balancing is never a 5 minute job"

True, maybe 15-minuets. Put the prop on the balancer. Mark the high point (light spot). Drill a hole as if it were for hub bolt such that the prop washer will hide it. Insert lead wire. Lead pencil weights for fishing are good for this. Try balance. Adjust the balance by trimming or adding to the the lead until it balances. Secure with a couple of drops of CA.

I spent way too much time spraying, drying , sanding and generally fussing around before I figured this out. This is how full sized props are balanced. The trouble with using spray finish for weight is that as the solvent dries it looses weight. Unless you let it dry really well it will go out of balance as it dries out more.

Thre are lots of ways to do things, I understand. I do think what I am doing has real advantages for wood props.