Most is too strong, but a fair number of the ones I watch do. The creator is upfront about the sponsorship so it is clear. Generally this means a big announcement and then future videos show the product. Wd40 sponsors several that I watch, and following the sponsorship the channel was careful to point out they were using Wd40 for whatever. (in most cases the video would have been about them using something before like wd40 before the sponsorship, but the what may have been hard to tell)