This is good advice. However (more toward OP), be advised that call recording laws like "two-party consent" (which means both parties must agree to the call) only means the call cannot be admissible in court if recorded improperly, not that you can't record it or that the recording is illegal.

A lot of companies with numbers you can call will say that the call may be recorded, regardless of where you call from. This is good because it covers their side of the consent. They cannot legally only consent to their own recording. Even in a state with one-party consent, once they consent to their own recording, if you record that, they just consented to yours. They might fight this if it goes to trial (it won't), but if you are in a one-party consent area, you can argue that you can disagree with being recorded and still have a right to call if you have business with them. They will argue and say your consent is absolute because you stayed on the line. If they say that, they're fucked — their consent becomes absolute as well. "What's good for the goose is good for the gander" for the most part. Also, with an iPhone, when you start recording, it plays a similar message. If you do that while they have you on hold, they won't record it, but it will be recorded on your end. They can't say "you played the warning while you were on hold, we couldn't hear it" because then you could say you couldn't hear their warning while you were on hold. After all, some smartphones handle hold for you, alerting you when a human comes on the line. Therefore, if you did not hear the warning and it's still valid, the same is true for them.

Alternatively, be more honest and start the recording when a human gets on the line. If they refuse to continue the conversation, you can at least assume they are up to no good. That should tell you all you need to know.