Candid, a 2 part borax to 1 part boric acid mix, works well as a fire retardant, insectiside and wood preservitive. Infact the use of antifreeze greatly improves the latter use.
Borax is a mild costic, so the use of boric acid balances it

 (my neighbor, Tahera,actually reports of dishes falling off shelves,in her kitchen, from where my primary hammer is mounted now)

I may have missed it in the thread, but if this is the case its probably the floor of your shop that is the problem.

If you pour concrete on bedrock it will transmit the shockwaves, you need to uncouple the concrete floor.

If airborne sound is the problem and you have firewood, place it strategically around your walls.