Unlined shrinktubes?

I'm back and have a question. I recently changed-out my pinchbraids with some less curly hair (I was the one who insisted that my french refined HAD to be deep wave cuz it was SO curly). Now that I have a bodywave installed, my braids are slipping out (guess the curls held much better in the microbraids). I remember that someone was talking about/trying to put some sort of shrinkie or something over a pinchbraid to help hold. The gal that did my braids said it would be a good idea to try this as long as the product didn't have adhesive. Is adhesive and silicone lining different? I can't seem to find anything like this quickly and you girls are so FAST and helpful, so I thought I'd "call in the troups" to help me locate something before all my money slips out of my hair. I was looking for something I could slip over the braids and heat up to seal the braid and string that would not be a nightmare to remove. The idea of glue or bonding material in the braids makes me nervous. Also, I am fearful of breakage from metal or some heavy product (why I went with the pinchbraids). Ideas? Thanks SO much!!!!!

Thanks for the info. Not sure yet what I will do. Is it better for the hair to have the lining in the tubes (silicone or adhesive) to keep water out of the braids? Someone mentioned something about the adhesive sealing the hair against water.