Perhaps make there be a small .01% (or configurable) chance that any barrel being cleaned is 'lost' due to being too heavily used to be properly returned to service? Barrels rust, get knocked about, etc, so some attrition makes sense and means there would be a consistent need for new barrels.

i dont like loss, what about a "broken barrell" which needs 1 steel (or just time??) to be repaired or something like this? Question is just, why, because htis mod already adds another layer, why add another on top?

Yes, I think nuhll is right. Although I have considered added an option when playing with bobs/angels that you will need to provide a cleaning agent for the process too.