You have an inherent problem in that, for any sort of wet cleaning, any cracks or breaks in the surface layer that allows moisture to get between the lacquer and the glass (or metal) substrate will end up delaminating the disc. Palmitic acid exudation requires much effort to remove, and in our study, different treatments work better than others depending on the chemical composition of the disc. We have not come across a dry cleaning method for palmitic acid removal.
Your best bet is to try different solutions - buffered Disc Doctor, Photoflo (diluted) if you can get it, or our method using castor oil and a bit of liquid soap afterwards. Use Q-tips or some smaller, lint-free material to do this surgically. Avoid the cracked edges.
You may not clean them 100%, but maybe to a usable extent.