Go for it John! I assume you are using that special stuff for making sticky maggots, the name of which I cannot recall! It is water soluble but should be fine! I have a tub but have yet to use it!
Sticky Maggot is usually used to project a ball further than loose ones with a catty.
I doubt a ball would stay intact for 4' let alone 18. Is your intention to use it on a river?
Also as what chrissh has said or use aquarium gravel instead of a pebble, some anglers use this in conjunction with liquidized or mashed bread in deeper or flowing swims.
I would think that in that depth of water most if not all would be taken well before they reach the lake bed, it may result in fish coming up in the water but if you want to be sure Simons suggestion of a baitdropper would be my choice.