I suggest the past tense form of the word "mint" should be "mung". It gives the proper feeling of what has occured.

A sample sentence, illustrating past tense. "Gee, King, too bad about that 'Stearly of yours-she is no doubt pretty badly munged after 6 months in the salty drink".

Another, this time in reference to a future tense possible gun problem.
"Best be careful with that screwdriver, mate-you don't want to mung that screw".

With acceptance, and practice, we will all come to know exactly what has happened when we use the terms, "mung" or "munged".
Best,
Ted