Sorry for the late reply. Holidays.
For anything but the most trivial examples, you'll find that the ASSL model is the only thing that works. Unfortunately, you'll find that CubeSlice depends to a significant degree on the infrastructure implemented by Microsoft. They've designed and developed numerious extensions to compensate for the limitations and inconsistencies in the Microsoft model, but unfortunately if you run into any complex cases they haven't accounted for, you'll be on your own. (There hasn't been a tremendous amount of industry interest in this product, pity since it's the best solution out there I've found.)
In general, you'll find that the answer will be to remove features and simplify until it works.
As to any other solutions, if you find anything, please post an update. In general, the world seems to assume 100% connectivity, which just isn't practical. (Imagine if your PC didn't work at all, if you didn't have a connection! Shudder.....) Coupled with Excel's general "chatty" nature, I don't see much relief.
There's some "screen slicer" solutions out there (they capture the various parameter selections and store it on the remote device), but I don't find they scale well (i.e. 100 products x 100 stores = 10,000 screen captures).
The BI industry is dying for a true offline BI experience, suppoprted on various mobile devices, but I haven't seen anyone step up to the plate yet.
Good luck and let us know of any successes.