Well, the feds taught me well.
WE didn't advertise as pest control - word spread rather quickly down here (media attention helped, afterall, wilt is an epidemic) and the fact that ALAMO for wilt is 8-18 dollars per dia. inch and still the tree's die - we got plenty of attention. Awards helped too, along with saving the oaks over L.B.J's grave.
When things got serious (Dept of Ag suits following us to treatments) I simply stated we're trying to wash the tree, you know, "hosing off all the pollution and stuff, making her smell better too". This pissed them off, I readily gave them samples, they quit bugging me eventually.
Calls kept coming in from distant homeowners wanting to know if I was the guy who washed trees - "yeah, you got it", and we'd schedule work if only the neighbors too would let us spray - sometimes 150 miles (one way) has to be justified. The cost is generally no more than ChemLawn coming to give your plants a nitrogen addiction (if you cancel ChemLawn, you'll notice your lawn will die - chemical withdrawl).
There is a difference between a licensed pesticide and a registered fertilizer. State Ag Depts. want all supplements to have a basic label, so with $15 per year, we registered "BioSave" (my bio-stimulant with trace N). The soap however, is babyfood. If someday the powers that be want total control (it's getting there, with machine guns to enforce them), the MSDS data won't be too hard to generate. It softens hands while you do trees!!
I have to admit - all the hundreds of billions in economy the AgChem industry deals with; all the stocks, bonds, deceit, lies, extortion, tests, results, more lies, deaths (and yeah, I consider cancer part of this industry because lots of the pharmaceutical industry IS the chemical industry), we have a pretty good time just rolling along, happily treating the poor sick trees with nothing more than a few bubbles and lemon (or rose if you're weird) scent. Oh, and getting results, that's a biggy.