We’ve had (drywood) termite problems on and off for years. Since there’s no way I’m going to have the house tented and permeated with Vikane gas,* I would periodically get the bug guys to do the microwave treatment. It cost $2,000 initially, then about $500 per year for future treatment when needed.(I believe orange oil is also used these days for people leery of insecticides.)
A few years ago, I decided to try Greenbug spray, which is (said to be) made of cedar and natural ingredients. I’ve been spraying this stuff on the wood where I see termite frass (pellets) and to my amazement, there are no more pellets. I say “amazing” because this is topical treatment and it doesn’t seem it would get into the wood where termites live. (All of our termites are in ceilings.)
The stuff smells great, like cedar oil, and I am just now buying a 2nd gallon (about $60). I pour it into squeeze/pump bottles (like Windex bottles) and spray until it drips a little (it’s water-soluble). Haven’t had the bug guys out for many years.
Greenbug is one of the few products in the world not sold by Amazon.
*First, Vikane is made by Dow — red alert. And, if it can penetrate into the wood and kill termites, I am suspicious of residual effect.