I agree 100% with Notes Norton rules.

"I preferred flat wounds on a P bass, and I liked them best when they lost their new sparkle."
"On the other hand, I love new strings on my guitar, for that sparkle."

Think about twangy slap bass in jazz jam session. If you do so as bass player, it will be your first and last gig in that band.

Good News.

I tried Mac's precept and it works fine for my case.

String cooking precept

1. pot
2. butter
3. salt
4. water

put water, butter and salt to the pot
drop twangy bass strings to be boiled in the pot
boil the strings half an hour
dry the strings