Yeah counterpressure bottler is the only way to make it really work. You can just put beer in there and cap it, but it'll be less carbonated.
The thing about bottling with a CP filler is you want to have a buddy there big time. The filler seals against the bottle, usually with a rubber stopper like a carboy stopper, so the beer can be filled under pressure. When you pull it out, it wants to foam, so you need to get it capped quickly. One guy filling, one guy capping is the only way to go.
Fun toy, for sure. Cheers!