Almost every donation bow I make receives snakeskins, for several reasons:
They look "Kooooooool"
They raise more money at auction (live or silent) then bows without them.
Waterproofing
I personally do not like the the look of sinew or rawhide (antelope rawhide is my preference).
Without knowing who the final owner will be, I like to add some insurance/protection; for everybody.
As for covering flaws, I have yet to see a bow that didn't have at least one...often in the snakeskin.
Personally, a plain old osage bow with some sploches (if that is a word) of black/gray paint on the back makes the best hunting bow, mainly because of the weight sinew/rawhide and skins add to the limbs.