Hi Carol,
Borax works great but is hard on plants, so I usually start with Oxi-Clean and a low pressure spray wash. Then recoat with Penofin if you can get it or BLO will be fine, but it doesn't have a UV blocker.
Insects are bad for houses; especially since they indicate that there is moisture in the log. Get rid of the moisture intrusion(most likely bad roof/wall interface flashings) and you are on your way to eliminating the bugs. Then bread yeast and
DE can be used to kill them if they don't just leave on their own. After removing the nests and decay and ensuring all is dry,then use a
wood filler. The best patch is made with nasty ole 2 part epoxy. I use Abatron.
All Blessings,
Bill