Rubber cement tubes are useful once. After that they will be dried out next time.

I just change my tubes on the road and patch at home, at home I use a big jar of office supply rubber cement, been on the same one for years now. It was two bucks. I do have patches and a tube of cement in my kit but I've never had to patch on the road.

Patches work perfectly well for me. A few months back I was tossing a tire that had 6 or 8 patches on it. I tried to pull them off and it was very difficult. I gripped them with a pair of pliers, I was able to get one or two of them off but mostly they were bonded so well that the tube ripped before they came off. I typically run 80 PSI.