okay, so yesterday I was experimenting. I tried the dental floss - used the glide kind, it is a little wider than regular floss and came from the dentist (you know those little samples) - it was too slippery! When I went to tie it, the ends just slipped out of my hands...perhaps another kind would work better.
Then I tried the elastic thread - it broke with my first tightening.
In another post someone mentioned they had tried organza but the 1/4 inch showed under a knot (and I tend to prefer knots) and the 1/8 broke.
So, unless I find another dental floss I'll still use embroidery floss. I don't pull the floss apart like for cross stitching. I use all six strands and since I have tons left over from cross stitching, I usually have a color that matches. Matching helps the color coordinating part of my brain. You know, like bra and panties being the same color, lol!