No experience with Interdeck. I have read positive results with this non slip additive from Behr with epoxy and have used it with polyurethane and had good results. Gives a good non slip that won't open flesh. Give the website a minute to load.

 Available at HD for about $5.

link

I used it on the deck of my old wooden Alden daysailer.  I like the feel & traditional beige color.  Cleans up pretty decent with a sponge & water.

I was talking w Larry Froley (designer of the clc kaholo standup paddle board kit)the other day.  He recommended Monster Paint. Says its very clear and compatible w varnish. 

Michael

I have used Interdeck for years on my sailboat. The stuff is bullet proof without being to abrasive on bare feet.