The epoxy/salt method does work, but a better method is to use what the custom and production board manufacturers use.
A coat of "thinned" epoxy resin and foam dust (applied from a regualr flour sifter like you have in a kitchen)
You would need to clean the deck of your AHD off with a solvent and then apply the tin coat of thinned spoxy resin (you can roll it on but spraying is the best).
The sift an even "sprinkle" of the foam dust over the epoxy and let the epoxy cure.
The also make some kits (Redeck) that have the resin and traction material pre-mixed, but I think you get a better job with the resin and foam dust.
You can check what Eva (The Board Lady) Holiman has to suggest @
Hope this helps,