On some of the old bait recipes like Nelsons the instructions always say to bury in a dirt trench for a period of time. What is the benefit of the dirt trench? I am thinking that it is along the lines of a steady temperature, no outside impact of light source of any kind and protection from bursting? Wondering though if I am missing something in my thought pattern on it?

More like a hole as opposed to a trench.
Steadier temperature mostly.
No protection from bursting, it still needs a one-way vent and covered securely to keep diggers out of it.

I prefer an old dead freezer, personally.

5 gallon pail in the shade for me surrounded by lilac bushes for a cool environment! With a sealed bag taped onto the bucket 1/2 way up.

If I did the bury in a trench routine annually I would have to buy a backhoe. No real need to do that for aging a product if that is your point. We do hundreds of buckets annually that must be monitored frequently. Aging indoors if possible in a controlled environment or as suggested use an old freezer or fridge to hold small consumer size amounts.

Access to the containers is important to check on the progress/stir and to check for maggots or fly larvae. These things can compromise a batch if not detected in time to correct the problem

No big deal with skunk pods nothing would survive it here. LOL

I agree with the aging skunk pods. I had 7 - 5 gal buckets 3/4 full when started 4 years ago aging. Had them in an open front out building where I kept some mowing equipment and our stored essence. Never had any fly problems to my knowledge.