Some time ago, looking for a way of using cocaine inside a disco, I've confronted with the idea of mixing it with physiological saline solution (NaCl 0,9%), inside a nasal descongestant tube. It worked actually very well, altough your nose get really really more 'off', and it's less harsh on your respiratory tract. I cannot determine if it is more or less potent than inhaling the powder directly, but it's more practical for using in public places.
The powder can be dissolved on it's own, or, melted, dissolved then put into the microwave for around 5 seconds to improve the dissolution. It actually worked for me, but I've only tried that once, for now.
[Erowid Note: There are many varieties of over-the-counter nasal sprays. Some contain active ingredients while others are only water and salt (saline solution). Cocaine should not be mixed with unknown active ingredients. It should also be noted that the damage Cocaine does to the nasal tissues might well be lessened by snorting liquid instead of powder. Sometimes a few drops of ethanol (drinking alcohol) is used to increase the solubility of cocaine in water.]
