Interesting situation.

What size and number of buckets are involved?

Roughly how many clusters/pounds of grapes are involved?

How long have the grapes been submerged in water?

What was the original intended use of the grapes?

Is the current flavor of one grape acceptable?

If so, juice the lot and freeze to use at your convenience.

Earwigs are the most likely insect to be found in a fruit cluster.

Brief rinsing and jostling of the grape bunches will remove insects.