I doubt many members on here have actually had it done, let alone done it themselves. There's only Kinnerly who I can think has had stuff dipped.
To answer your first question, there is a technique to it. It looks easy enough but you might not do it right the first time. The pattern can stretch and warp and end up looking quite shite.
Even if he'd got it right, it would look bad anyay because it's UCP!
Some people insert the parts in at an angle, I've seen others dip one side in and then flip it over to do the other.
To answer your third question, yes it's very durable. Especially considering it's primarily used on real guns and car parts etc, it has to withstand a lot of wear and heat. Should last ages.
In terms of ease of doing it yourself, most videos on YT look like it's a company with a professional set up. Other than dipping, you need to paint the parts first and clear coat it afterwards as well for the best finish.
Is it worth it? Well, taking a look at Camo Lab's pricing structure, a pistol frame is £30. A full rifle on the other hand, from £100 to £130+
Depends on what you're wanting to dip.