Ok, I did the foam rubber grip.
Here's what that Crayola Model Magic package looks like,
and the finished product.
I wanted to do Black, but that only came in the deluxe kit for 10 bucks. I don't how much this one was supposed ot be, because it was mismarked and I got it for a buck.
I have to let it dry 24 hours before I can report if it's durable enough, but it sure is a lot easier to hold now.