Stop with those five seconds for crying in a bloody bucket. Giving the advice to "only use five seconds because YouTube won't pick up on it" is risky. I've seen shorter slices of music perfectly being detected and claimed in the past.
Fun fact: Content ID not finding something will potentially be caught by a human looking for it which won't only get the video claimed/blocked but your channel a strike with a high chance. You don't have a good time with strikes (not only because it breaks the Freedom dashboard lol).
Back to the main question:
If the content is used to enhance the rest of your video you can do that BUT your own content skills have to stay in the middle of it and the video should not create a market substitute for the original.
WHAT DOES THIS MEAN?
If you make a video using an ad for Franky's toilet paper and talk around it it should be fine. However if you decide to reupload it without adding your own content to it it isn't. Also if you create your own ad for your own toilet paper and use that part of Franky's advertisement where the woman smiles it's also not okay.
Fair use is complicated, general rule of thumb: If you make your own video and need to use it to make the video better, go ahead but with common sense.