I've used Bike Register on all my bikes using the permanent marker kit.
You need your frame number, bicycle make and model. Buy the kit on the website and they post you a unique kit to mark your bike. You can also upload a photo & description too.
The permanent kit marks your bike with a unique number and the bike register web address. If you're careful you can use it again to mark other parts of your bike too.
I don't see the point of the extra UV kit. It will only work if the police recover it or parts of your bike end up in a crime scene, sadly I've never seen anyone with UV torch when buying second hand parts.
I doubt many people will run a serial number of a second hand bike they're thinking purchasing through websites like Stolen Bikes, it would be nice if they did but I'm skeptical that the general population would.
I feel people are more likely to check Bike Register as its obviously marked & stickered than they are to check a frame number on an unmarked bike.
The Bike Register sticker serves as a deterrent to opportunists.
I've sure someone mentioned on here buying the unique kits in a shop, marking their bike but not finishing registering it on the Bike Register website unless it it's stolen as they fear hackers getting the address of their desirable bike from the database.
But none of my bikes are nice enough to make it into any shopping list for hi-tec thieves.
It also gives peace of mind to potential buyers when you're selling one too. All you need to do it's enter their email address when you sell the bike and they can update the bikes owners details themselves with the new details.
I have heard of someone selling a micro-dot marked bike, then years later having it returned by the police because it was recovered but the new owner didn't update the micro-dot details and the current owner was untraceable, but don't know if it's true or whether you would be allowed to keep the bike in that situation.