I've had the ACF-50 treatment done, about a year ago, and yes I am aware it comes out everywhere
The reason I would like to buy my own kit is because getting it done is a bit of a hassle. I have to fly the plane somewhere, then (on an owner assisted basis) I spend a couple of hours unscrewing the various inspection covers, then the man goes around and sprays it (and rips off some piece of wire which he didn't see) and then I spend another couple of hours putting the covers back on, and then I have to fly back before my home airport closes.
If I could do it myself, it could be done inside 1 day, easily.
The actual spraying is really quick. Well under 1 hour to do the whole plane.
The spray device is 2-3 rods which screw into each other to get the reach, plus a nozzle at the end. Plus a B&Q-style pump-up spray thingy, IIRC.
I am a long way from Essex... well, would have to fly.