In this video youtu.be/UrX3wm1nSOg?si=F5dswE-5PRCc2QIN from 2:55 Holly shows a quick clip from a video of her feet being tickled by her friend. She also mentions that she posted the full video in a vlog, as of now I haven't found it but if anyone else wants to have a look to try and find it it should be in one somewhere!