I share this method of grafting that I've been working on for a while. It has ok results. The advantage is that you can graft young seedlings and the stocks only takes a couple of months to produce. Also no annoying spines like on pereskiopsis. Both stock and scions are around 8 weeks old.
Probably not suitable for variegates though..
First cut roots off H.justbertii seedling stocks.
Next rub off the spines.
Then cut roots off scions.
Then rinse with water, dry them, and rub with alcohol to sterilize.
Cut scion and stock and stick together.
These are the left overs..
Put the grafts in a food container with a moist tissue to create humidity and cover with food wrap. After this wait about a week for the grafts to heal. Take the tissue out after a day and put holes in the food wrap to gradually ventilate the container. Treat the finished grafts as small cuttings. Pot them up and cover the pot with clear food wrap with a few ventilation holes so they don't dry out too much before roots grow. After 3 weeks roots should be enough to just treat them like normal H. justbertii seedlings.
After 1 year...