Yah, i know, but thought it was apparent that i was speaking more theoretically or hypothetically.
Ime, it's not that hard to replicate an EPIC like silicone coating. Basically it's similar to reproofing silnylon. I used pain thinner, the more expensive silicone adhesive stuff, took a hand held blender and blended it up very well.
Threw the garments and/or fabric i was treating in the dryer to warm them, and as i was applying the slurry to the fabric, tried to stretch out the fabric. Used a foam brush to initially apply, and then took a microfiber cloth to rub it in more deeply. This was all done on hot summer days, outside in the sun.
It's probably not as even or deep as factory made/applied EPIC coating, but it will be worlds better than cheap silicone spray, and probably better (longer lasting) than a factory fluorocarbon treatment. The Maxima ESD polyester fabric that i treated this way, is now quite water resistant. I now have a front chest panel of this on my otherwise non breathable poncho. It may leak a little sometimes, but i'll also have a houdini or the like underneath that i could zip up, so i'm not too worried about water ingress.
Anyways, if you look at Richard's quotes again, you'll note that supposedly some EPIC treatments for some fabrics last a rather long time. Hence, in my mind, it just makes sense to combine an EPIC like DWR with other WPB tech, like membranes. As i've said, the only problem with this, is that eventually it may wear off, and the average "consumer" isn't going to do the above process to recreate the DWR. This may be the main reason why EPIC and EPIC like processes aren't used as DWR's for WPB tech that involve membranes or the like, that and/or cost.