You should set them aside for about a week to form a callous, then pot them. Treat them like your other aloe plant, and don't over water them. They should start to grow within a few weeks after establishing a good root system. To use the gel, just snap off a healthy looking leaf, hold it with the snapped off side face down to drain the laxative sap out, and then rub the gel wherever you need it. If you only need a small amount of gel, I believe you can just snap off the tip of the leaf and rub that on. The leaf should heal itself. I'm no expert though so you might wanna do a little research before following my advice. I've only transplanted an aloe offshoot once and it was a large one that had it's own root system developed already.