I know more than I ever wanted to know about prickly pear (Opuntia) pads. Processing them is a sticky business. There are two kinds of spines. One is large and prominent, fairly easy to shave off with a knife or shove. A shovel would actually be quite good, because you don't want to get too close to them. Around the base of the clusters of these spines are smaller, very sharp and very numerous "type two" spines. These are the worst. They get everywhere and are very difficult to detect, even after they have punctured your tender body parts. The best way to process the pads is to singe off both varieties over a fire.

Evidently, he did not encounter any cactus fruit. They are sweet and quite tasty. When I lived in Arizona, I made cactus jelly jam and syrup quite easily. Yes, the fruit carries spines as well.