To smoke hash oil with a spliff, add the hash oil when rolling on top of the herbal weed. This is a good way to add a kick to cheap pot. It may take some practice to get it smoking properly. It’s also possible to add on top of the weed in a bowl. Dab it on to the side of the bowl to avoid it saturating the intake, but not too close to the side as to miss the weed, as pure oil is more likely to catch fire. You want it between the intake and the bowl edge, on top of the weed.
Many people know to decarboxylate cannabis in the oven first, but it’s worth noting here for anyone who doesn’t know or doesn’t see the point in doing so. You can skip this step and add your raw cannabis to the slow cooker to decarb in the oil, but you might find that this longer oil soak simply worsens the taste of your cannabis oil. It’s also more difficult to control the temperature in a slow cooker and you risk burning off essential cannabinoids, but in an oven, you can set the temperature low and keep it steady.