As there is practically no one size fits all, you can gain some legitimacy by understanding and applying the binomial based plans of FDA's qsit inspection guide. This can fit the per sample item good vs not good audit claim under the normal conditions allowing you to make some statement concerning the larger population with some robustness.
What remains critical in this is the actual method of randomly selecting suitable items, keeping sample homogeneity in mind as well as knowing how to care about type 1/type 2 (false positive/ false negative) errors for your conclusion.
Do beware that, though not huge, they remain time consuming amounts of items to assess and depending on scope you might not manage. The correct way to proceed is to be aware of and communicate the lesser certainty. (Don't go for the generic "alas audit is sampling based, bladibla"; just nuance your conclusion or state inability to make an unambiguous one you dare to stand behind. )