iv had problems with it leaking.. well not getting to the tank. but i found it was my seal on the bottle. although once i took the whole thing apart and put it back together. with vasiline that seem to work for me.
It's very strange, had one bottle going well but it was started to slow or stop, but rather than renew the solution, I added a "T" piece and a second bottle. I have a professional tube clamp, when I clamp off either bottle,
the bottle builds up pressure but when the two are connected, they seem to loose pressure. Maybe though it is a lid, I've just tightened one of them.
my co2 system has 4 bottles :L using 3 t peaces iv got no leaks (at the moment) normally when i do get a leak its a seal on the bottle. all the bottles have 1 way valves as well so pressure isent lost when i change 1 bottle (i change 1 a week)
Sometimes the problem with DIY co2 can be the airline itself, Regular airline tubing can seap co2 through the material due to its lack of rigidity.
Co2 tubing is tough and stands up to the job better, however due to the lack of pressure in DIYco2 i cant see this being a problem, worht a try though!
If your going to run DIY co2, you might as well make the job as close to perfect as possible, as it is so hit and miss, the slightest leak and you do not get the results you are aiming for.
My advice if you wish to gain good results on your set up, By co2 tubing, drill the holw in the bottle cap lid slightly smaller then the tubing diameter. Dip the end of the co2 pipe in warm/hot (not boiling) water to soften it up and allow you to manipulate it though the small hole, allow to cool, then silicone the tubing,
Also, good practice to silicone the T-valves as these let air creap too!