As for jogging people's memories...

So whenever i have to get approval from higher ups that i know they will forget and get annoyed about it i ask that they all stand up and state "i agree / approve to XYZ." People will laugh and say "really?!?".

At my last job one of my bosses decided on something that went against what all us in engineering said. So i told him to stand up in front of everyone and say "i acknowledge that this goes against the suggestions by engineering but I would like the team to implement.... whatever the feature was." Two months later he came to a meeting all pissed about how this feature wasn't working and when he saw me enter the meeting he said "fuck, this is my fault isn't it?"