from what I have been reading, most people who boiled any of the atty's has killed them. The sonic cleaner seems like a good way to go, I just ordered one myself, and hope to revive a few clogged attys of mine. What I have been doing to clean mine, is simply running warm, but not so hot you can't keep your fingers under it, tap, then blow dry(mouth) to get excess water out, then use my electric blow drier on the cold setting to help get more of the water out, then letting them sit, thread side up, over night. This has kept them running for a while, but they do eventually get so much gunk in the fiber glass and mesh that you can't just rinse them clean. This is where I hope the sonic cleaner will come in. I also found another thread about carefully removing the mesh/bridge and fiberglass threads out of the atomizer, exposing the coil, then I carefully take a safety pin and gently scrape the build up off the coil, trying not to damage the coil. The hard part is not pulling the inner workings out when you remove the bridge. I use a tooth pick to hold against the ceramic piece inside while I carefully pull up on the bridge, after removing the mesh. I have done this to several of my 510 atty's that I thought were dead, they heated up, too much, and no longer produced vapor. I quickly found out why, the coils were crusted over and not making contact with the liquid. Also I think the air hole was getting blocked by the gunk. Now, I have to advise you only try this on atty's you know are not working right, and you have exhausted all other possibilities of cleaning/replacing with warranty etc... The only down side to removing the wick/bridge is the constant need to drip. But I have been working on a screen mod to fix this problem (at least for my 510 atty) that has been working pretty good so far. I have posted my findings about this in these threads:
http://www.e-cigarette-forum.com/forum/cartridge-mods/38161-brass-screen-mod.html
go to pg 19 and scroll down to where I have a photo posted, and my mod.
this is where I found the info about recovering your dead atty:
http://www.e-cigarette-forum.com/forum/polls/56499-510-atomizer-resurrection-mod.html
I am not taking any credit for coming up with these idea, simply expanding on them, and trying to share the info where I feel it will be useful.
I don't know how easy it will be to remove the bridge/mesh/fiberglass from the 901 atty since it is much deeper, but it is worth a try if it is heating, but not making vapor. Better than just tossing it out, without a try. I regret throwing away a few atty's that would not vape, but got hot. I just thought I had fried them. Good luck!
BTW, I just got my slim today, tried it out, and it worked just fine, though it does have that black greasy stuff on the threaded ends, not sure why, I found that to be a little messy. I am still deciding if it will be a keeper or not, just because I am testing out many other mods right now. I have nothing negative to say about the function of the GG slim at this point, I tested it with both the i3 and one of my 510 atty and got good vapor from both, once I broke in the new i3. After a few good puffs, I took off the i3 and rinsed it clean, set aside to dry, in case I don't keep it, I want to keep the atty in good condition for the next person. I will keep an open mind until I have a chance to get used to it, and also try out a few other batterie mods.