non-skid material for a plug

I am building a plug for a swim platform and would like to mold the non-skid in the plug. Has anyone used a particular material for the plug? I know they make Flex-mold but it would cost too much for a 4x10 area. I did find one material I think will work for the pattern. The 2x4 clear plastic lenses on drop ceiling lights have a similar pattern. I stopped by Home depot with some of my kids play dog and made an impression. It looks like a good pattern. Does anyone else have an idea? Oh I guess I should stop staring up at the ceiling at work (this is where I got the idea)

 

Use 2 x 4 ft rectangles of pebbly clear plastic used normally for drop-in ceilings for light fixtures.

 

You looking for an effective Non-skid or a pretty one?

 

a finish look and yes functional

 

Spray it to a taped pattern.