Yea I meant do. Darn auto correct.
Why would it be illegal for the easy seal?
You need EPA cert. To install easy seal?
You need an EPA cert to attach anything to the system that has a possibility of releasing refrigerant. So he can't legally connect a can of stop seal to the schrader fitting of his system, if its an R22 system.
EPA section 608.
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.