[Mark1]

In my non-legal opinion:

Bear in mind, if push ever comes to shove, it will be very difficult to convince a judge and jury that you performed corrosion treatment procedures, performed them regularly as a normal course of your business, AND that you performed them for free, or a very low cost.

No business can survive by providing services below cost.

If it's the liability that you are seeking to avoid, I suggest that you photo each and every job you perform the procedures on. That way, a judge or jury will at least believe that you performed the repairs, and that you weren't a very good businessman for doing so at low/no cost, as opposed to no photos to show proof that you did, and you therefore might be lying about working for free. After all, few work for free and stay in business long.

Just a suggestion, but remember, others do perform the treatment, and charge a fair price. And we are paid by customers, and insurers, to do the work. More and more insurers are wising up and realizing that the treatment costs are a pittance when compared to the liability of death or injury they are indemnifying under the policy. That's their business, assessing risk. It was only a matter of time before the insurer bean counters saw the light, and the savings, though some insurers went kicking and screaming until the photos traced the previous install back to their own perferred installers. Then they began to see the light also.

Just a thought, HTH.