Hash oil? For sure. If you've ever had a pot brownie, then you've already tried it (I hope, anyway. 99% of pot brownies use hash oil. The other 1% someone who is new uses the whole bud. Yuck. Gross. Also less effective than any other way of using the plant). Ditto, most edibles at dispensaries / cafés? Use Hash oil/ can ibis oil. Some use straight hash, but the oil is easier to work with in most cases.
Eating
Heat releases the cabinoids (not just THC but all the volatile psychogenic chemicals, to greater or lesser degree), so cooking with hash oil is generally not the best idea... Although brownies (cooked fast, at a low temp, in a dense substance) loses less than most ways. Still, if you cooked them covered? The moisture & oil on the lid would get you high as blazes, even though many of the cabinoids completely are completely broken down by the heat. And brownies are the best method in a bad lot, really, of actually cooking. In general if you want to eat it? Don't cook it. Don't heat it at all. Drizzle the oil over pasta (or whatever) after-after-after you're done cooking it. Or the oil can be drizzled/dripped onto bread, salad, etc.
It's generally best to not mix it with other fats, as the oil can bind to certain kinds fats, trapping the cabinoids / making them all but inert. They'll still enter your system, but at a much slower rate, and to far less effect. Meanwhile other fats actually help potentiation release of the cabinoids into your system. I can never remember which is which, so I always just kept it simple & avoided oils & fats (cheese, butter, yogurt, avocados, bacon, etc.) ahead of time, or with, as a general rule.
Smoking
A few drops can be heated on tinfoil & you can chase the dragon (running a lighter under it, and following the smoke stream with a straw), or you can drip some on buds you'd be smoking alone. By whatever method you usually smoke pot with... Although the shortest delivery method is best. Small pipe & you'd lose the least amount of the chemicals to resin on the glass. Long hookah? You're gonna lose a lot to it coating the sides of the tubes.
Vaping
Possibly the single most effective method, it loses the absolute least of the chemicals involved, and doesn't have the raging amounts of tar & carcinogens
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Why I keep on about losing the chemicals... Hash Oil / Cannibis oil is made from silk screening off the crystals off of MJ buds & leaves. The sticky crystals are then pressed into cubes that look a bit like chicken bouillon cubes -but are as sticky as gum in your hair- and later diluted with oil to make a viscous liquid. It's a labor intensive process that decreases the value of most MJ plants used to make it (the buds that have had their crystals rubbed off the outside are still always sold, but except for certain strains, rarely at more than half what they could earn otherwise). Both of those two things together, the time & money lost, mean it's expensive if made well (and not mostly plain oil inert oil). Wasting 1/2 to 4/5s of the cabinoids in the oil by cooking with high heat, or resonating your devices? Makes it both less effective than smoking pot (so you might as well just smoke the plant), as well as is a big waste of money.
Also, clearly, since hash oil comes directly from the crystals in the plant... There are as many varieties of hash / hash oil / cannibis oil as there are plant strains. Different strains contain different levels of the chemicals involved. A good producer (dispensary, cafe, etc.) will be able to tell you not only which strains were used (often several, sometimes single source, depends on the grower), the percentages of each chemical (there are tests), & the % of hash to oil. ALL of which are going to affect the final product. If you're doing it yourself? Rubbing the crystals off of your own buds & dissolving in oil? 1, do go to the trouble of looking up which oil to use! & 2, The effect will be remarkably similar to whatever plant you used smoked whole, just much, much, much stronger & faster.
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Disclaimer... I haven't smoked pot (or ingested any other form of MJ in whole or in part), in well over 10 years. Yeesh. Pushing closer to 20. Used it during my last tail spin. So there may well be other methods employed these days. Eating, smoking, & vaping were the 3 most common back when. Eating, by far the most common of the 3. LOL We didn't even have the word vaping back when, although that's what suspending it in oil and heating at low temp to vaporize the chemicals is.
Also to note: BHO (butane extracted hash oil), is a very different creature than HO/CO. I think it's called Dabs, these days. None of the above is good advice for BHO. Using BHO like HO/CO could actually kill you. Also, don't make BHO. Hash oil is easy/safe to make at home & as legal to do as any other way of ingesting it. Making BHO can blow up your house. Also, illegal. (I call that "duh" illegal. In addition to being dead? You've also committed several crimes. Whee.) So Don't. Just don't.