I think it was Ricky Tims but someone showed a tip of taking a piece of freezer paper and ironing it to the design wall. peel it off and it takes the stray threads with it.

I just use my clothes brush, you know the one in the back of closet that you dig out when the cat gets to close to your black pants. Yup, that one! A quick brrrrrush and the wall is clean of threads and little this and than and ready to go!

When my DG's were they used to pick the threads off for me. Now I use to hold sma quilt and things.

I have an old style lint brush that has a bed of what I call velvet, with a nap. Brush it in one direction and it lifts the lint and threads. Brush in the opposite direction and it releases the all the collected debris. I have had it for years and it still works. What I really like is that I don't have anything that is trash going into a landfill. I use the lint as fire starter for my camp fire pit.

I think a modern version is available at JAFs.

I took my design-wall flannel bed sheet and washed it. Only about half of the treads came off. I had sprayed the wall with adhesive so my squares would stick to it. So everything did. Now I will try some of the other methods. I have a lint roller that can be washed and reused. That feature is very nice, but I'll have to see how it works on threads that have been stuck on with spray adhesive. Even after it has been through the wash!

I've tried several things and I finally used the lint brush that has bristles like a hairbrush. It takes everything little thread tail off my design wall.

Lint roller!!

dog brush
 

I tried vacuuming, tape, red velvet lint brush, tape lint brush, ironing freezer paper to it and the only thing that worked was the slicker dog brush! its a small brush with a couple hundred stiff wires on it. the only thing is that it also takes the flannel, so I wouldn't want to do it often as pretty soon you wouldn't have any flannel on your design wall!

This is the kind I own - it's a big heavy-napped fabric that works like a charm! No need to keep replacing the rollers...just wipes clean or launders well.