We have performed a computational search for probable inhibitors of SARS-CoV2 papain-like protease, and validated the likelier candidates through molecular dynamics simulations and PMF computations using unbrella sampling/WHAM. Despite the promising nature of the computational results, experimental validation returned disappointing results. We have succesfully pinpointed the origin of the mismatch between computational promise and experimental failure to the deficient solubility of the candidate compounds, which leads to their aggregation in solution. A simple molecular dynamics protocol we developed can succesfully distinguish between soluble inhibitors and aggregation-prone molecules, and we suggest that it be incorporated as a standard tool in computer-aided design workflows due to its modest computational cost.