Repair man recommended pookie?

I know absolutely nothing about AC units or really anything mechanical. AC stopped blowing cold air last night. He came out this morning and ran some tests checked my vents and went up into my attic and ended up getting it to work again. I asked him how he fixed it and his response was “I guess just show up” meaning it was some minor thing I guess? I’m a shy girl and didn’t ask a lot of questions when I know I should, but he recommend I clean my AC unit of debris on the sides and said something about getting “pookie” and sealing some area around my vents?

Can someone explain to this ignorant 1st time home owner what he’s recommending I do to maintain my unit? Photos would be helpful. I live in Phoenix where it’s currently 110 and ac is critical.