Is there anyway to verify transactions with an unknown wallet?

I'm basically looking for some kind of online tool, dapp, or a wallet that allows you to verify eth transactions with a wallet that neither you, or anybody else know the secret phase for(ofc this tool needs to be legit).

A fellow redditor posted a comment about this tool in a thread of mine in this sub and refused to elaborate, hence why I'm asking about it. It kind of doesn't make sense but I hope to use it in my multi-sig wallet if it actually exists.