Do you have a link to the YouTube video?
Well... While there are still numerous videos on there showing how to do this, the one I liked best has apparently been removed, because it's not even showing up in my watch history with the others. I'll try to summarize the process.
To start, you need to clean your top really well with soap and water. Once its dry, wipe it down with a clean tack cloth or lint free cloth.
Now some people wipe or paint on the Penetrol and just leave it. I'm not sure I can recommend that. I see a couple of people saying wait 25-30min and then wipe it off. I'm pretty sure I only went 10-15min between applying and wiping off.
I applied the Penetrol with a microfiber towel. After 10-15min, I wiped it back off with a lint free rag (I think I used an old t-shirt).
If you let it set for too long, the Penetrol becomes super sticky/tacky and it gets very difficult to wipe it off.
Once I applied and wiped off the Penetrol, I gave the whole jeep a good wash. Three years later, I don't notice any fade. Now that said, my jeep has been dirty for the last 3 months, so if there's any fade now, it's happened during that time. I'll be trying to wash it this week and I'll evaluate it at that time. If it appears to have faded, I'll go ahead and Penetrol it again.
I want to stress that this was on a factory 2002 hardtop. I have no idea how well this method works on aftermarket tops. I've seen several people use it on factory flares as well with great success, but it didn't do anything for mine, although I suspect that has to do with the previous owner trying to restore them with a torch.
When I get a minute, I may organize this post a little better and repost it in the how-to section.