[NIH_IC555]

Hi, today I performed something called the "blue bottle" experiment, based off NileRed's video(source:https://www.youtube.com/watch?v=6sJbNRSCoMA) for a chemistry project at class. It's been a hours since i finished and the reaction turned yellow as expected and i neutralyzed the leftover potassium hydroxide with vinegar as suggested by my teacher however i didn't do anything to the solution itself with dextrosed mixed in with KOH and methalyne blue. My question is, should pouring vinegar into the solution be enough to neutralyze it or do i need to take additional steps now that all the chemicals have broken up? And after neutralyzation, is dispossing of it by letting it go down my house sink something safe?