as noted, butyl tube material is to flexible to protect the real tube from damage by a spoke/spoke hole.
Also noted - old tubes make great elastic tiedowns, I've used old tubes (the thinner, 18-25 size), split down the length, as underlay for real bar tape. Adds just the right amount of 'cush' to the bars and keeps the bar tape from moving/migrating. Also adds a touch larger diameter to the bar size, which is welcome for my hand size.
Also, length of inner tube, split down length, makes a great temporary frame guard, if you transport your bike in side an SUV or van. Keeps rub marks from developing from the bike rubbing while driving somewhere. And/Or depending on what kind of external carrier you're using, again a good frame guard to resist wear from carrier hold-downs.
A bazillion good uses for old inner tubes, but rim strips is not one of them.
Ride On
Yuri