i assume you are taking the cowards way out, rather than doing this the way Its been done for hundreds of years.
my sugestion comes from the original methood, and might work.
1..... use a much bigger piece, which extends bellow the waist band on your underwear.
2.... use a needle, and thread the cotton under it,
3.... dont try to hide the balance of the thread under it, Instead, just have it hidden in your underwear, or have it hang down the leg of your trousers.
I hope this is all clear.
you're like Yoda.you dont say much, but what you do say is worth listening to....
Greg Wilson about.... Me.