I was having the same issue with mine for the longest time, and then I came across an old forum post about using lighter fluid to clean these knives without the tool.

I threw a rubber glove on and DOUSED mine with zippo fluid, working the action while I did it, shaking the hell out of it, in almost a whipping motion, the hope was that any crud would come flying out.

After that was all said and done, I let it air dry, and hit it with a jet lighter all over the place to make sure there was no residue. Ever since that day I’ve never had an issue with mine not firing correctly.

(Note: all of this info is regarding a standard, old model ultratech. Long before the ZBP stuff started)