Foaming agents for drywood termite treatments

Does anybody know if there are any foaming agents that have been approved for use in California by either Do-It-Yourselfers or Pros with termite treatments (e.g., Premise, Termidor, or Bora-Care)? I see that's Masterline Foam page says it is "not for sale in California" and's Termitafoam page says it "cannot be shipped to AK, CA, NY." I haven't yet contacted local outfits.
If I fumigate or otherwise kill active infestations, will foaming or spraying into wall voids protect the studs from -future- drywood termite infestation? Does the foam or spray settle so that only the support beams and the lower portion of the studs are protected? Is foaming or spraying about as effective or nowhere near as effective as a "protectant" than injecting studs and beams directly?
Thanks in advance to all,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.