Slippery tile fix

[Live And Learn]

My front porch has nice tile but it is very slippery in high humidity. I don't want to replace the tile. Right now I have a couple of extra large doormats strategically placed but I'd like to remove them and show the tile again.

I've been looking at products like "Johnny Grip" or "InvisaTread". Does anyone have any experience with these products or anything similar?

Thanks