I should warn you that DensShield is a gypsum based product. It's esentially a fiber reinforced drywall with a waterproof vinyl face on it. So if you're dead set against any gypsum based products don't use it. In my experience it's the mudding and sanding of drywall that creates all the dust. If you pre-cut your dens outside and bring it in you should have no dust.

Like I said before: do not install Kerdi over den's shield. You will create a vapor lock. This means that the moisture in the thinset used to put up the kerdi is sandwiched between two layers of waterproof materials and will never dry out.

PistolPete, thanks for that! I have been scratching my head over exactly how there would be a problem, and you have just explained it.

Thinking about all the options, I trust the seal from the Kerdi wrap. One distributor told me to seal right under the drywall and onto the flange of the tub.

No panel-plus-liquid could seal that thoroughly. Jaz said this:

"Use regular drywall, it's better (stiffer), than green board."

I find that surprising. I thought the green layer was the only difference.

I guess I will have more dust to deal with.

Hello, I used Green-E-Board for a tub surround and used Red Guard liquid membrane over it. The Green-E-Board was easy to cut with a table saw and it is very ridgid with no tapered edges if butting up to drywall.

It seems to be a good alternative to cement board with less granules shedding from the board and has similar water resistant properties as cement board.
Just a thought and may be another option.