David, I agree with Don; any fabric that will hold the electrolyte properly and conform to the stencil should be fine. I use the "batting" for the same reasons as you use felt: when the original stuff ran out I went to the fabric store and bought something that looked like it as close as possible.

It's spun, sorta like fleece, but it's meant to "stuff" inside of sewing to give loft and body. It is much like a felt. It's a tiny bit thicker than flannel, but I don't feel that'll matter near as much as the other components of the process: stencil type and design, electrolyte choice, wetness, voltage, and operator technique.
I don't think you are looking dumb; I don't think you steered Alex wrong.
I just happened to know that different manufacturers supply different stuffs for pads. I figured if he went to the fabric shop and said, "No, that's not it" to felt, then maybe he could say, "Could I look at quilt batting or facing?" That'd just increase his chances for finding what he was trying to match. They tend to group fabrics together; I was just trying to send him to an alternate table in addition to your felt suggestion.
As for a foto, my camera isn't exactly Joe Macro. I don't think I can get a good close up to show the detail without pixelating. Sorry.