Cleaning projection screen

From what I read so far water seems to be the best option. I am trying to clean a PVC front projection screen that has random marks on it and is visible depending on the angle of viewing. Are there better alternatives I can try ?

From what I read so far water seems to be the best option. I am trying to clean a PVC front projection screen that has random marks on it and is visible depending on the angle of viewing. Are there better alternatives I can try ?