LOL about the 'blowout' in the diapers!!! I'd forgotten those experiences, and have some fond, but foul memories.

And about mixing your fibers for the reinforcing of heels and toes....That's a great question!

I'll give you my thoughts, for what they are worth. Maybe others have additional comments?

I think you are correct. Using something harsher than the base fiber can be a problem. Tho I have to believe the reinforcing yarns sold, most w/ the 20%nylon content, are safe enough to use. In theory, nylon adds strength to the wool, and prevents the stitches from disappearing, altogether. It extends the life of the wool. But given the use of the hose, and the abrasion it goes through, especially while in your shoe... I doubt you'll find anything that's indestructible.

W/ Dad's hose, tho, the yarn was 100% wool, and in addition to using the reinforcing yarn, I used an old/ancient soft floss that usually shredded while I used it on my teeth. I wouldn't suggest GLIDE. I actually considered the monofilament nylon thread, but rejected for the very reason you brought up.

Given his toes, it's not really a matter of <if> there will be a hole, but <when>. I wanted to give as much reinforcement in the toes as possible, from the get go. I can't over emphasize how gnarly his nails are.

His hose are three years old, and no complaints to date. Maybe moths will be his bigger threat? That would be ironic.