A live dump showed DrumCleanLog_'s newest entry moving every 30-90s on
its own, including well after a cycle had already finished -- it never
settles on a value worth showing. drum_clean_cycles_remaining, read from
separate WashingTimes_/DrumCleanProposal_ counters, is unaffected and
stays wired.
The washer/dryer readers this was originally built from (issues #9,
#258) aren't touched -- no report of the same churn there.