Answer:
Rinse with vinegar solution several times.
Step-by-step explanation:
The objective of conditioning equipment is that any impurities are removed before using the glassware in the experiment.
Another reason for conditioning is that any drops left in the glassware are from the intended solution and not water, that way the concentration will not change. However this is why washing thoroughly with soap and water would defeat the purpose of conditioning. It's possible to first wash with soap and water and then rinse with vinegar, but not viceversa.