White grapefruit is the only one with narangin, the essential ingredient. Pink has no effect. Now understand that white grapefruit will dramatically increase the intensity and duration of the experience, and for some, render it unpleasant. I use it because my tolerance to DXM is high, and I don't want to get into stratospheric doses.
For me, it took 300mg every two or three hours for about thirty hours. I went through a total of twelve bottles of Robogels on this particular trip, if that's what you're after. I don't recommend this to anyone flat out. Put it in context. I have a high tolerance to DXM, as well as extensive experience with psychedelic trips. Believe me when I say there were some scary moments - indeed, hours, during this trip, and I do mean scary. People who know me personally in this context know that when I say a drug experience is scary, I mean its enough to make most people go ahead and call 911. Scary to me is not a bad acid trip. Scary to me is not an ego death. Scary in this context is: I condemned my spirit to hell, and I'm the only one in the universe forever, and death is not possible. Eternal solitude and madness, growing in geometrical degrees. The physical discomfort would be something yearned for, if only to confirm that I still had a body. You get my meaning here? This is not for the fainthearted. I'm not suggesting that you are not qualified, I'm simply clarifying my terms so that you don't get yourself into something you can't get out of. That being said, I will reiterate that it was by far the most beneficial drug experience of my life. Worth it? For me, yes.
As for the diet/ supplements: Fast for 24 hours prior, with the exception of some tea and maybe one protein shake several hours before dosing. No heavy fats or sugars, period. No junk food. No candy or snacks. Plenty of water. A vitamin B complex, biotin, vitamin C, and some watermelon and lemons on a plate in the fridge (you will eat these throughout in order to stay alkaline). As you experience hunger through the trip, eat the watermelon first, along with a glass of water and a vitamin B complex pill. You only need to take the B pill once every 24 hours remember - no need to overdo it. Take the C upon cessation of DXM intake - start your first C intake when you feel yourself coming down. Again, just take it reasonably, no need to get crazy, but take enough. I took around five grams throughout the trip in its duration, so you can see I take lot for this. I don't recommend hyperdosing C consistently. Next, you will want to intake a good green supplement - the best is definitely wheatgrass - you can order green kamut in powder form online or just go to your local healthfood store. Wheatgrass is wheatgrass, it doesn't need to be fresh to work its magic. Wheatgrass is an invaluable tool in maintaining health through heavy drug use, especially DXM. One reason is the potassium depletion that results from heavy usage. Keep your electrolytes balanced and you won't experience all the reported negative physical sides from DXM use. I know this from personal experience. Best of luck with your trials - get back with me and let me know how it goes.