Freshly crushed garlic cloves release a very potent antibiotic called allicin which is very potent against most types of bacteria, fungi, protozoa. The half life of the allicin in very short so the cativity of allicin is destroyed withing a few hours.
Frozen crushed garlic retains the allicin activty for a relatively longer term that is why it is more active than the garlic powders which are sold in stores and in most cases have no allicin activty whatsoever.
As I said the most potent is to crush a garlic clove than then extract the allicin with 50% ethanol and this si a very potent antimicrobial which can be diluted with water.
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