The only problem with those is the metal band around the bristles...isn't there the potential for damage, and aren't they going to rust?
I use vinyl electric tape. Easy to apply and works well. You can also use it to stiffen up a detail brush with long bristles by kind of a modified back taping. Start by taping the ferral; then twist the tape 180 so the sticky side is up. Now tape up the bristles as far as you prefer; twist the tape 180 again so the sticky side is down and tape down the brush to the ferral.