SpearingMN,
May I suggest, since your state doesn't allow dropping materials PERMANENTLY on the lake bottom for lightening your hole and view....run this by your DNR officials. I think you can beat this law legally.
In my exploration of Youtube pike videos I came across someone (I think it was across the "pond" in Europe) that dropped a washing machine top lid (dryer would work too) on the lake bottom and it didn't seem to bother the pike nor inhibit them from coming into and over the area. I've used white paper napkins and paper towels in a pinch on the bottom, then at the end of the day just dropped my spear on each of them to retrieve.
But with the washing machine lid you are dropping it down with a line attached. From a legal point you aren't really "polluting" the waters by having that material in the lake as a benign retrievable object, no more than having a boat floating in the water calling that polluting. And since you will be retrieving the door when you leave there is no "littering" of the lake bottom. Its just another tool you are using for your pike spearing. I think you can get away with this as long as whatever you use has no polluting capabilities and is retrievable when you are done.