Step-by-step explanation:
Methanol being a polar organic solvent, can dissolve polar contaminants whereas hexane being a non polar solvent can dissolve non polar contaminants.
So, if they are used together, we can dissolve most of the contaminants to wash out the glass.Moreover, both these solvents have relatively high vapor pressure at room temperature and pressure than most other solvents. Therefore, residues evaporate rather more quickly.