I didn't watch the whole video, but I can tell, I put way less in my cubes and they work good. I use 30k diff oil everywhere and I main a weilong at the moment. The way I do it : I use a tooth stick, I put some oil on a plastic board and scrape the surface of it with the stick so I have a little drop at the end of my stick. Then I use this little drop for each edge of my cube ( I usually only do 4-6 edges ). Then I work it out for a while add 2 drops of maru lube inside it, do a few solves and let it rest for a while. Once in a while I do the whole thing and unmount the core, clean up the pieces with paper, and lube screws / washers.
Also, I find that overlubing screws and washers is way worse than overlubing the pieces ( if you overlube the pieces you can just take a few out, completely wipe off the oil, work it out a bit and do it again until it gets good ), but if the core is over lube you definitely have a gummy sluggish cube and you need to unmount it again to clean it. So for the cube I found something that works good for me, I just put a few drops on a piece of toilet paper, and just slightly pass it on the parts I want to lube, so that I only leave a thin layer of oil.
In anyway, this thing really works like salt, better not enough than too much. If it isn't enough, you can always add more, it's always more work to remove it.