As for your first solution: according to the law, if you do have relevant evidence to prove that the other party has infringed, then as an Internet service provider, if you still don't delete the infringing content, you may have to bear the same tort liability.
Relevant legal basis: Interpretation of Several Issues Concerning the Application of Laws in the Trial of Computer Network Copyright Disputes. If the Internet service provider who provides content services knows that the Internet users have infringed the copyright of others through the Internet, or has been warned by the copyright owner with definite evidence, but still fails to take measures such as deleting the infringing content to eliminate the infringement consequences, the people's court shall, in accordance with the provisions of Article 130 of the General Principles of the Civil Law, investigate its tort liability with the Internet users.
I think your second method is feasible, but if there are many manufacturers, it will cost a lot of money to explain them one by one, and many manufacturers are very cautious about products with intellectual property disputes. So you may need stronger evidence.
You can first notarize the relevant web pages to fix the evidence of infringement. Then you can negotiate with the infringing company by letter in the name of the company. I think this may be more labor-saving than the second method.