Indeed if you are spending all this money on very pure silver you ought to make sure you yourself know where the moon is at a particular stage of its cycle. Being a mundane astrologer aswell as a training herbalist I know the next two years moon dates more or less off by heart, and this is the level of accuracy you should be familiar with when charging your CS with lunar assistance. Sometimes the moon is in aspect with some of the larger planets whilst full, if there are any negative aspects at the time of the full moon, you must always be aware that they will be fully applied to the silver at that time also. Saturn is a planet of contraction wheras Jupiter is a planet of expansion.
For example a hard 90 degree aspect between Saturn and Mars whilst Saturn is opposite the full moon may not be the most approriate time to use the full moon to charge your CS.