I've CK1'ed before, and my opinion on the matter is: if your're sniffing coke and get offered K to add to your high, do it. If you're doing ket on the other hand, unless you know you'll be seeing it again soon, besides for a first time to try it, you usually odnt want to dirty up the clean ket high with coke. However, some ket added to a coke high can be reallllllllllllllly nice. Note that random fights have broken out amongst almost everyone whom I gave this combo to while they were drinking alcohol, so I wouldn't really add that to the mix too, I never have. Calvin Kelin'ing it as some may say is definately a bizarre high, can be enjoyable at times but I don't know if I'd do it again. I'd reccomend nitrous and coke for a good stimulant/dissociative rush/combo personally, the rush to that is amazing.