I also wanted to try slime tubes but really hated them. They are filled with liquid which adds weight, drag and unpleasant water shedding sound if you listen carefully. I doubt if they will be successful preventing a major leak, but if they do, they will most likely create a mess inside the outer tire. I would much rather carry a spare tube. If you need extra protection, I would be aligned to use tires with built into 1mm, 3mm, or even 5 mm protective belt, depending on your protection needed.