Has anyone used this for repairing a flat mid rails to trails.. does it work well.. i think i read you can also inject it before an incident and it should auto seal..

I'm just wondering if this is fools gold or if it really works, or is too messy to deal with in the end (when changing tubes eventually)?

I do carry spare tubes and usually canisters of air, along with a slow pump (manual) but was just wondering if this offers adequate protection or a quick fix in the event everything else fails

Thanks in advance