For anything important, use matrix instead of lemmy DMs.
I couldn’t find it using the model number on fccid.io but it might be that the dishwashers themselves aren’t FCC certified and they only send whatever wireless board they add to it.
Usually can find anything that has radio signals with teardown pics, etc.
IMHO it’s not just about the messages but whatever else the app might have access to just by being installed on your phone.