I am not trying to take the credit for this - but if you are going to alter wads.....why not make them yellow.....corn yellow.
If they are going to bio-disappear in a year it would be nice for them to look like a small ear of corn laying in the stubble....field...marsh until that happens.
And for the record...put me down for a no....I wouldn't shop for a shell that was specifically bio-degradable.....if it was convenient to purchase and economically alright to do so I would but when I need shells I go buy them....I wouldn't look around for them.