Tube cement, which brand is best?

I've got a bunch of patch kits that contain yellow "Propatch" cement
tubes. On Sunday I had to use a kit, as usual for another rider. We
found the hole, sanded the tube, opened the li'l cement tube ... phuffff
.... only air was left inside. It was inside an extra plastic wrap and
all, didn't help. So we had to use my spare tube.

Do you guys know a brand that is better and where a bunch of these
little tubes could be bought sans patches? Not so much for me but for
other riders because many reported similar problems.

--
Regards, Joerg

http://www.analogconsultants.com/