My personal strategy is to heavily play with the displayed stuff in a randomized fashion...
...and washing my hands afterwards...

seriously: I own almost a copy of jochens display case and use collector cards acryl boxes for extraordinary figures and customs.
my playmo ships I have for display in the double faced windows in my appartment are doomed for dust...
...as long as my son isnt asking for them.
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(...but never forget to wash you hands afterwards.
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)
best,
socrates