How would it or could it? By the power of the spoken word. (and Jesus told them and us to do it). ...and, "As often as ye eat this bread and drink this cup,"...doesn't exactly say to limit our partaking of Communion to once per year.
Sanctification and purification is a drawn out process and takes time. As far as I know, there is no scripture which prohibits our taking Communion privately in our homes or even daily. Ritz crackers work great and any wine will do. There may be a big benefit to taking Communion that many do not realize, that it is in fact. more significant than we have realized.
I don't think that Communion is symbolic in the least. Before we receive it, we give thanks and bless it, and declare, this is the Body of Christ, this is the blood of Christ...and...no one really knows what effect this may have in the unseen spiritual realm or to us here on earth. All we know is that, life and death is in the power of the tongue, we are seated in Heavenly places with Him, and it was HE that created everything with a word...then must have thought that for us to take Communion was important enough to tell us in His book to us...
So, why? I think because it is part of the sanctification process and very seriously helps in that process. It's main effect is within the spiritual realm that we do not see, but Communion is in no way symbolic because of our spoken word before partaking of it. We do do it in remembrance of Him and His sacrifice for us, but there is more to it. It must help.
Our God is a nice guy so did not require for us to actually eat bloody flesh in the natural realm so makes the change from bread and wine to flesh and blood in the spiritual realm when we give thanks and bless the bread and wine.