By doing this I am opening myself up to MASSIVE criticism, but the best thing I have ever used over an extended period, is a 60/30/10 mix of rubbing alcohol, acetone, and windex ( or any comparable glass cleaner.
Yes, I know that rubbing alcohol isn't supposed to be a degreaser, and yes, I know that acetone can be harmful to your equipment if used improperly, and I know that windex is not a degreaser.
I am not advocating the manufacture or use of this concoction, I am just saying it works for me.
I know I will most likely be lambasted for this, but it really does work for me, and I have kept balls alive for longer periods of time than most by using this mixture. I have never had any detrimental side effects ( balls cracking, balls softening, particles melting ) from using this mixture, but I use it in very small quantities, using it only as a superficial cleaner. If my equipment gets to the point that it needs more than this, I take it to an approved shop to have it done, but this seems to lengthen the time between having to have them professionally cleaned and re-surfaced.
Just call me Darreyl, it's much easier to say!