This I believe is the most informative video when it comes to making mayonnaise at home. Personally, I think anyone who adds carrots or raisins in coleslaw - Is commiting food blasphemy! So such people should be tied to the rear tow hook of my car, then dragged on the Karachi to Gwadar coastal highway, (630 kilometers, 392 miles)! Best coleslaw is nothing but cabbage (shredded very thin), and mayonnaise - Like they use to serve in the good old days...
My Mum made homemade mayonnaise all the time, back in Australia where I grew up. Except we didn't call it mayonnaise, we called it salad dressing, because it was only ever used on salads, and not sandwiches. BUTTER was what you put on sandwiches!! I had no idea what jarred mayo tasted like until I moved to the US, and I thought it awful stuff! The only thing I would add to that cole slaw recipe is some celery seed. Don't knock it till you've tried it!! It's a very subtle taste, but makes a really good difference imho.
I have made my own mayo but it was when we had our own chickens and eggs ! For me,, i have to have Miracle Whip ! On a bologna and cheese sandwich with home grown tomatoes mmmm !!!