With a wet Erlenmeyer flask, the result will not be accurate. It might be contaminated by any type of liquid such as basic or acidic. Therefore, an error will occur since it is not 100% acid.- hope this helped
Your results would be effected because there is a possibility that the water and chemical substance added into the flask will combine, possibly creating a reaction, either making the solution stronger or weaker, or possibly just messing up your experiment in one go.
For example:
If I paint a picture, and I have a cup that I use in order to put paint in, but the cup is wet and I put my paint in it, my paint will become more liquefied due to the fact water has been added to it, messing the paint up.