Short of that, like I said, but it up your nose. Cocaine has a short half life (90 minutes) relative to most stimulants, so no matter how good it is, you should be coming down in 45-60 minutes. On the cleanest, strongest coke I've done, I was able to sleep 2 hours later. So if the shit gives you a rush, and you're ganking for more an hour later, it's pretty clean. If your heart is racing and you feel that artery by your temple beating when you put your head on your pillow 3, 4, 5 hours later, it's cut with cheap stimulants.