Many years ago I tried freezing perch guts from my previous perch trips, put in handful of gravel as ballast, in a plastic bag. Drop only frozen chum after removing bag. It occasionally helped attract perch and catfish. The bigger the bag, the bigger the chum ball, the slower it would melt down releasing the fish pieces. You defiantly you could see it attracting a bait ball on fish finder!
This is a useful way to recycle what you usually stink up the neighborhood with until the trash collector picks it up!