I find usually clearing ones flash cache, browsing history and browser cache is effective primarily after there has been a game update or if one is having problems with the game itself, not vem.
Clearing it every time one plays or often has a negative effect as it deletes files that are used that do not need to be re-downloaded into the cache every time one plays the game thereby has one effect of slowing down the loading time for the game. I guess if one does not mind having it load slower or having to reset their game options then it's ok.
VEM= Virtual Equipment Modulation a whole nother topic within it's self