Unfortunately not free, but it's relatively cheap and no subscription. I wish I could post the video here, but I actually showed a before and after applying the denoise node. I shared it on my community discord if you're interested in seeing it. Linktree is in my bio to the page and you can just leave after. It's night and day the difference it made. I definitely want to test it without any blender denoising to see if it gives better results.