What would be the safest way to drop thousands of small, hard objects from a typical, high wing, GA airplane? The subject pretty much states my question, now I will provide a bit of background.

A family member, who lived on the west coast of Florida Manasota Key, collected tens of thousands of fossilized sharks teeth between the mid-1940s and the late 1970s. I have now become involved in deciding what to do with these sharks teeth. Here is one of the multitude of pictures available showing samples of these types of sharks teeth:



The vast majority of this collection ranges in size between a dime and a quarter and likely has the same level of hardness.

If you've visited one of the beaches in this part of Florida in the last 25+ years, you probably know that finding these treasures is no longer as easy as it used to be.  When I was a kid (late 1970s), I could usually come up with 10+ teeth in about a 2 hours stretch.  However, by the time my kids were of the age where this would be of interest (early 2000s), we were lucky if we found one a day.

What I'd like to do is return these teeth to the area just off shore of this beach thus giving future searchers a better chance of "re-finding" them.

Let's assume for the purposes of this question that the airplane involved would be a Cessna 172S. What would be a good way of doing such a drop without harming the aircraft itself?

I assume just dropping them out the window risks blow back that could damage the aluminum fuselage or tail assembly.

A couple of notes:


This is NOT a question about the legality of dropping items from an airplane in the United States. I am well versed with 14 CFR § 91.15 - Dropping objects, which states:



  No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.



I am not interested in a solution harmful to the environment. Thus dropping them in taped boxes or rolled up newspaper would not be warranted, because that would be littering.
I'm certainly aware that renting a boat and dropping them off the side would be an alternative. That said, for the purposes of this question, I am specifically asking how to achieve this using a Cessna 172 (or similar) high wing GA airplane.
Funeral homes sell gum bags for ashes. They dissolve in the ocean, releasing the ashes. You could make satchels and drop them in bundles with the teeth wrapped in kelp.