Stay with #44 flux and avoid water clean
I agree about 63/37. It flows better than 60/40. If the OP is just soldering a few coils then either is fine.
Wondering what you don’t like about water soluble flux. I used to use it for small run production because it did not require chemicals to clean—easier handling. Agree, no-clean leaves residue so you still end up cleaning.
OP, Kester solder is good stuff. Just clean the joints with a little alcohol when you’re done.