"Medical" marijuana is typically smoked, and because of this I can't agree with its use as "medical", though it would fit the mainstream definition of medicine, ie a drug that masks symptoms but does not treat the underlying problem or the whole human animal.
Cannabis however can be consumed orally in different forms. Either cooked in to butter and then used in baking or as a spread, or extracted in to some carrier lipid/fat/oil such as olive oil or an alcohol such as ethanol.
Hemp oil, when referring to the food oil, is not psychoactive and I would guess in most cases is not truly raw.
Yes, anything a bunch of potheads can do, is fairly simple
haha! Cooking with cannabis and other extraction methods are all pretty straight forward. If making butter it's just a matter of simmering the butter/herb long enough to allow the cannabinoids (the active compounds) to migrate from the plant material in to the fat.
Or if you're making an alcohol extraction like green dragon then it's only a matter of having high enough quality herb and as pure ethanol as possible. Then you can either accelerate the extraction with heat, or leave it at room temp and give it a long period, a week-3+ months. Then you can consume the alcohol directly or if you're looking to avoid the onerous health effects of it, you can evap it off and then take the residue orally. Or probably the healthiest would be to extract it, cold process, in to olive or coconut oil over a long period of time.
I think it's like 1 to 1.5 oz's of quality herb per pound of butter. Not sure what the figures are for the other methods.
And depending on what variety and your growing location, 1 plant could produce between 1 and 32 oz's of dry flowers (the active part of the plant, sort of). It depends on a lot of factors, your yield. For example, if I were to grow here in WI, at latitude 47ish, I would have a very short growing season and would have to go with either a pure indica or a hyrbid species that leans toward the indica side, and I'm probably looking at a couple oz's per plant unless I started them early indoors with artificial light. Of course if you're growing indoors then that is a whole other animal.
However if you're in the philippines with a long growing season, then you could grow the more potent tropical sativas, which take many months to finish but can produce 1+ lbs per plant. So, basically if you're growing big plants in the tropics you can get by with less plants than you could in a more temperate northern climate.
For personal use in your area, for a whole year's supply, I'd say you could get by with between 1-3 plants/person.
But here in the north climate it might require 3-10 plants to keep one stocked the whole year.
If you do decide to grow, icmag.com is your place for info. Also a heads up, cannabis is made of male and female plants, the female plants with their rich production of cannabinoids are the one's you're after for 'medicine', males are only fractionally as potent.
There are other methods of extraction I could mention but they are not health conducive at all.
The one last thing I'd mention is that most of the active compounds are in the crystals (trichomes/resin) that coat the female flowers, if this material is manually concentrated, ie hashish, then you will start out with purer material. Resin is akin to hard liquor while the whole plant material is more like beer. This can be done cold process without any heating whatsoever.
I don't know whether the 'real' medicine is in the plant material itself or mostly in the trichomes, or if it's really efficacious at all, so that is something someone else will have to chime in on.