I plugged a barrel and filled it with #9 to set overnite and to pass some time I read the directions on bottle. It stated do not cork the barrel and I got to wondering why? Can this solvent damage the innards of barrel if left soak, or are they covering liability issues in case a barrel obstruction is left in barrel. I understand the nickle issue but did get to wondering my soaking overnite. What say the experts, shall I fear or fear not?