Frozen only makes it much harder to inspect them & realize they aren't completly insect free. Washing & brushing strawberries do not clean ANY of the insect hiding under the seeds (even a wash cloth). The washing of spinach, lessens the incidence but does not eliminate.
Therefore the proper method for consuming those vegetables is to purchase nice fresh brocolli, cut off all of the florets, wash check the stems & cook. The nutrients are in the stalk, the protein that's in the florets are not permitted, get your protein somewhere else.
The above method has been recomended by some of the public speakers e.g Rabbi Eisen among them.
Strawberries- cut off the stem & leaves with a sliver of fruit. Either peel the strawberry or wash a few times with soap, then puree and cook.
RE; Mites- They aren't finding them, not that they aren't there.