Hey, unfortunately we don't allow these kinds of questions (source discussion, even if the drug is legal), nor do we allow the use of SWIM or anything similar intended to avoid self-incrimination (they can make your post hard to understand without giving you any real legal protection).
It's up to you to decide whether it's worth the risk,but honestly if you're already a minor I'd probably advise against abusing cough syrup for some fun.
Please have a read over our forum rules to be sure you don't waste your time asking something that ends up being closed off good luck!