Do exactly as Trisikad said, but if you have grime on the outside of the downstem as well I suggest using a ziplock bag and filling that up with ISO and Salt. EDIT : By the way, don't use some cheap plastic bag, as the very cheap ones can't hold Iso very well. But don't worry most bags are durable enough to retain it. Hell I keep some in a bag if I end up using too much and it's still clean.
There is a better way. Iso and salt works really well for the bong itself but the downstem and slider are a bit more tricky. Here is the best method: Take a tupperware that will fit both. Fill the container with seltzer and lemon juice helps. Then microwave it for a couple minutes. All of the resin will literally wipe off. A pipe cleaner makes a quick job of the inside and a paper towel will clean out the bowl in one sweep. I clean my pieces about every 3 sessions too. You got to. Its classy.
buy a cheap bottle of iso. open it up, (mine has a pour spout for convenience) pour some on the stem, and inside. stem, slider, bong, bowl, or what ever. put some iso on it. and use warm water. and use a folded pipe cleaner. no need to do elaborate shit. seriously. iso cleans it all good. I'd know cause ive had stems stuck in my bowl. and when people used my bong without cleaning it the stem eventually got stuck. took me an hour to work at it with iso and salt to get it out but just iso and salt. and water. use your bathroom sink. its best . trust me. easy tooo __________________________________________________________________
Don't use warm water to dilute the Isopropyl. Use it merely to rinse your piece out of all the excess Iso afterwards. There is no point in taking away from the Iso's potency by diluting it with water.
Definitely go with ISO, the higher percentage of alcohol the faster and easier it will clean the stem. But as some said earlier throw it in a ziplock bag and shake. Or any other container that will not harm your stem when you shake it around. You can use salt or rice as an abrasive but salt for all intents and purposes will work better. I usually buy the 91% alcohol and 70% because you can get the bigger bottles of 70 for the same price as a small 91. Then just use 91 for the initial grunt work and final alcohol rinse to get it real sharp.
Large zip bag, put in stem, put in ISO soak for one hour add salt, make sure to add enough salt until it stops disovling then shake it for a bit then work all the gunk off
what I use for mine is I dip a pipecleaner (like 3 bucks for a pack of 100 at CVS) into 91% Iso and it comes right off. Pretty chill
Never really needed a ziploc for the stems. I just load it up with salt, pore some alc in and plug both ends with my fingers. Then just shake it like a can of spray paint, UP and down. The salt does most of the work while the alc cleans it. Ziplocs work good for slides though. With this method there is no need to soak, atleast for me it cleans after shaking the salt inside in about 2 mins. 91% iso is the stuff to use, also its dirt cheap.
I know everyone is gonna say it's a waste but i bought grunge off and the stuff is even better than iso, Just put some inside the piece agitate to coat the inside....let it soak....(pour off cleaning solution into mason jar, you can use it more than once.) Rinse well with hot warm tap water. Comes out crystal clear guy at my LHS said he'd be willing to take back pieces that had been cleaned with it... It leaves no residue and contains no abrasives...also remove the dirty smoke smell from your piece.
ISO and salt gets a vote from me (and shake in a bag, works great and its quick). Simple green works great also.
Honestly dude, I just hold the stem and bowl under the bathtub faucet with hot water after every use and keep them in this small plastic box used for storing food that I keep full of soapy water. Save a couple of spots on the inside of the bowl, they look totally new. The bong itself really doesn't get dirty, I just keep it under the faucet also. By the way, this goes without saying, but be really careful when you fill up your bong. My brother had a nice bong that I broke accidentally when I hit the bottom against the rim of the bathtub. Whenever I handle my bong, my first priority is making sure it is safe. But yeah just clean it after every use under the bathtub faucet, I also use Q-tips to wipe away the tar. Happy toking