@Willie
I don't know if this is a viable alternative to your "gravel."
I bought each of these paint mixers for my drill.
The skinny mixer is a perfect fit for the opening of my 3-gallon water jugs, which are similar to the typical 5-gallon water jugs you use in a water dispenser.
The fat mixer I use when I use a 3-1/2 or 5-gallon bucket for mixing.
When I use the skinny one, it is a tight fit. So, as I am pulling it out of the jug, I make sure to get a good grip on the head, just in case the Chinese glue gives out and that head drops to the bottom of the jug, never to be gotten out. : )
Another way to say it is to imagine that you are helping pull a baby out during delivery. : )
View attachment 202449
View attachment 202450