I checked out the web site for RV Fog Doctor in AR. They have a pretty comprehensive video explaining their process and plugging their company. At this point, I believe most of these places use the same process and the primary variable is their warranty. I have several choices and I will select one based on our travels.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.