Crisco is great! Perhaps you tried it with your client and have enjoyed the results yourself?
The drawback with Crisco (and any other oil-containing substance) is that its not compatible with latex.
Now that incompatibility may or may not matter. But its important to be aware that oils and latex do not mix!
Personally I prefer to limit my use of latex, thus my go-to disposable assplay gloves are nitrile (gratuitous image below).
Although my opera-length fisting gloves from Mr S are latex, so when I'm using those, I opt for "You'll Never Know it Isn't Boy Butter," a water-based lube that is made specifically for assplay.
Its my back-up lube and what I like to travel with because not everyone is as familiar with the joys of Crisco.
(Enjoy this image of Zoey Zacquery and I in our Mr S gloves and imagine we are about to do to a lucky gentleman)