the krokodil part is smart! krokodil is desomorphine, a semi-synthetic relative of morphine and a cheap alternative to heroin. it is about 10x stronger than morphine, it has one less double bond than morphine and one less -OH group (morphine has 2 OH groups and desomorphine has 1), the more OH groups a chemical has, the easier it desolves in water and the less it has, the more fatty lipids it contains, making it easier to pass through the blood-brain barrier. Desomorphine lasts only half as long as heroin meaning you need to take more for an effective high and it therefore has a higher risk of addiction (aka, if you're manufacturing it, ka-CHING!). Not to mention, it's incredibly easy to create, with its base ingredients being mostly readily available codeine, paint thinner, hydrochloric acid, iodine, and phosphorus.