You have two choices:
1) Live with the spirocores and learn to get the most out of them
2) Play ring around the rosie with a bunch of other strings. You may luck out, but since you like the way spiros work pizz, chances are you will return to them and have less money in your pocket. You will have a bunch of used strings laying around if you ever want to fall off the wagon.
FWIW, I struggled through this same process and found that black bow hair does grip better but can sound raspy. I do use a Gollihur german bow with black hair. Pops rosin never worked for me. Oak medium or Kolstein soft work better. That's my $.02