Good morning : you can try the following protocol : after a first rinsing with DI water, fill the vials with sulphochromic solution, and let them 12 hours at room temperature. Then, remove the sulphochromic solution (it can be used for further utilizations), rinse abundantly with DI water. You can complete the washing with a ultrasonication followed by a final rinsing with DI water. Be careful because sulphocromic solution is very caustic.