Been using my DG for 3 weeks now and I love the thing. It's definitely my favorite piece for any application minus oil. I love to smoke with it but I rarely smoke. I use it with my VXL Cloud daily and it is simply incredible. Seems like they were meant to be used together. I also find that the main frit stays pretty clean with vaping, the small pre-frit takes the brunt of the impact.
I also found my own technique for cleaning the DG from any horrible state to like new in only a few minutes. It only requires about 1 - 2ml of d-limonene. Here is what I do:
1)Add water to just above the frit (warm is better but it doesnt matter, thats how well this works).
2) Add 1-2ml of d-limonene to the water.. THROUGH THE MOUTHPIECE! Do not add it through the slide stem part... because you will be putting your mouth there and it will be nasty.
3) Put your mouth on the slide joint and give it a good 5-second blow. Because d-limonene won't mix with water at all, it will sit on the suface and be thoroughly agitated by the bubbling.
The first time you do it, the bubbling will be tame and not go that high.
4) Now do another 5-10 second blow. Each time you do it, the bubbles will stack a bit higher because there will be more tar/THC dissolved into the limonene making it thicker. The excellent diffusion also means excellent cleaning action!! Do it until clean. Best to point the mouthpiece over a sink, since you want to stack the limonene bubbles as high as the "gunk" is. I place my hand over the top just as a precaution so I don't have limonene rain coming down on me one time
After only 5 or so blows through the slide joint, the piece should be basically clean. The limonene will now be orange or yellow but still sitting on the surface of the water.
5) At this point you can rinse with lots of warm water to get out the orange smell, or you can use a small amount of alcohol which will get rid of it much faster. Be smart about dumping the limonene, don't try to force it down through the frit to dump it, pour out the way it came in, and rinse water flowing that same direction at first, then it's ok to switch and force water down the frit and OUT the slide joint.
This is much faster and more effective than just using alcohol, and lets you use FAR less chemicals. A bottle of limonene should last years.