Scoring the pods is a waste of time. Use waste ground and plant a load of them, somewhere off the beaten track, and whilst during the point where they should be watered (when they begin to pod, starve them and give them the bare minimum, it helps to concentrate the goods and make for better quality pods). Scoring is both a potential giveaway of them being there as a result of wild escapes going to seed and spreading, is labor-intensive and a pain in the ass, plus there is, if all you take is the latex that dribbles out of the shallow cuts made, a LOT of product wasted that remains behind in the capsules.
Best way to do it, is just to cut them off without scoring, chop the heads off and a few inches of the top of the stalk then reduce the pods and straw to mush in a blender with some added water, (if you have a soxhlet and flask so much the better, use it for a more exhaustive extraction), its more convenient to use a mixture of alcohol and water, with the liquid rendered slightly acidic with a little hydrochloric acid or citric acid etc. to help pull the alkaloids into solution. A buchner funnel with a frit plus a decent sized (1-2 liter perhaps) isn't going to cost much, make it one of the type that has a vacuum hose barb on the side, and then one can attach a bit of plastic tubing and use one of those handheld trigger-operated vacuum pumps used for emptying brake lines, or a water aspirator (cheap) to make the job of filtration both faster and far more efficient than relying on gravity filtration.
They aren't really fussy as far as growing goes, and whilst they will appreciate some fertilizer, can be grown on waste ground and be pretty prolific.
And once a solution of the alkaloids is obtained by such an extraction (best to do at least two, as many as three pulls (or until a drop or two of a pull no longer tastes extremely bitter), the morphine and other phenolic alkaloids can be precipitated by adding a calcium base, because phenols are, despite their similarity in many respects to alcohols, far more acidic than alcohols and require a far, far weaker base as a result in order to deprotonate them and form a salt (compare with an aliphatic alcohol, to form an alkoxide requires a strong base such as dissolving lithium, sodium or potassium metal in the alcohol (anhydrous of course to avoid nasty explosions resulting from the metal reacting with water in wet alcohols), whereas a phenol can be deprotonated with weak bases such as slaked lime (calcium hydroxide), which, given the tendency to formation of insoluble salts of calcium, forms calcium phenoxides which can be precipitated out of solution. These can be regenerated into soluble form by acids.