^ Don't use cream on shell. See link...
You can use leather conditioner cream on shell such as Venetian Shoe Cream or Saphir Renovateur (both are actually great for shell in moderation), just not cream shoe polish is what Alden recommends not doing.
This however goes against what AE recommends since their own Cordovan shoe polish is a cream based polish, not a wax, and they source their cordovan from the same place Alden does, Horween.
So, I think basically you are probably ok with a shoe cream polish, although a wax polish would probably give you better results. Note, only a tiny amount is needed for shell and probably only like once every 6 months or something.
Edited by phototristan - 1/24/12 at 2:33pm