I suspect that a claritin D box and pocket scale is not the only evidence the government has to support their allegation of conspiracy to conduct a meth lab. The requirements in most jurisdictions if not all to prove a conspiracy are an agreement between two or more persons to perform a criminal act and then an overt act by at least one conspirator to carry out the act. Whether the actual crime was committed or not doesn't matter. The theory of conspiracy is based upon the intent of two or more persons who not only agree to commit a crime but take it a step further and perform some action in the furtherance of that crime. Evidence of a conspiracy can often be proved simply by proving the underlying crime occurred. For example, two guys go into a liquor store to rob it, both have handguns and both get away with the cash The conspiracy could simply be proved by showing both were present and acting together. Based on the facts you have provided it is unclear whether the conduct in your case would be enough to prove a conspiracy. I hope this helps.