i understand what your saying
i dryed them out on my roof though
and they didnt cause any harm
to my plant's last time and
i read that fruit farmers would
put whole rinds around there
plants to produce high yields
i'll try to find the link later

and the kool-aid container
is now used souly for that
purpose(and the plate kinda vanished)
so no worries:] for me atleast


NOTE: if planning on using kool-aid container/plate again
soak in a bleach solution of 3/4 cup bleach for every gallon
then wash with dish soap too