Yesterday I bought two boxes of Sicilian cactus (Opuntia) fruit (4€/1 kg) at the local supermarket. In Sicily I learned how to pick, soak (remove the spines), peel and eat prickly pears. Picking Indian figs (as they are called in many places; in fact it is in their scientific name, Opuntia ficus-indica), is a demanding and even dangerous job, as their thin spines (glochids) fly everywhere and far, even when the fruit is removed from the cactus with a long picking tool. This means you have to protect your body, eyes and lungs from these nasty spines. The cactus fruit is placed one by one in a bucket filled with water and allowed to soak until the thin spines on the fruit are removed, and then rinsed once again before peeling. Fortunately, grocery stores only sell spineless cactus fruit and there are many videos on YouTube showing how to peel and eat them.
In Sicily, I learned that you first bite off a piece of fruit pulp, then gently press it with your tongue against your palate and swallow it. So you can swallow the seeds, but you shouldn't bite them because they are very hard. You can spit the seeds out, but you will lose the fibre. Prickly pears are a good source of fibre and are rich in vitamins and minerals.