Water or Other

So my friend wants to put delysum in his bong and I'm unsure to whether or not it's a good idea.

Idk about others here, but I personally wouldn't mess around with cough syrup in a bong or bubbler. Soda, juice or some other non-alcoholic drink sure (using alcohol in a bong seems like a waste to me, use something else and drink the booze), but not cough meds. Then again, I'm the type of person that only drinks and uses MJ - don't need any other highs.