Cleaning Your Stem
Cleaning your stem is probably the most important aspect of cleaning your hookah, but regardless, it's possibly one of the more overlooked aspects of cleaning your hookah that I see (or don't see). A stem brush is the best investment you can make for cleaning your stem, though it isn't completely necessary. First, run hot water through your stem. This will help get the majority of the glycerin that will drip down your stem between sessions, but sometimes not all of it. I usually run hot water through my stem three or four times. If you've run it through a few times and it still smells weird, I generally take the same hot water, lemon juice, and baking soda mixture that I use in my base and run it through my stem. Hold the bottom of your downstem so it's plugged with your finger. Next, pour the mixture into the bowl port. Once it's all in there, plug the bowl port with your other hand, and shake the stem. Do that for a minute or so, then dump the mixture. After that, run hot water through the stem a few times. You can substitute this with using a stem brush with a bit of soap on it if you have that readily available to you. Make sure you take your purge out, completely disassembled, and scrub the purge ball. If it gets too much gunk on it, it can easily get stuck, and make it hard to purge. I generally recommend running hot water through the hose port and the purge port as well, just to get any ghosting out of those areas as well.
Cleaning Your Bowls
Bowls are just as important to clean as the rest of your hookah. It is what's heating up the most of anything throughout your session, and needs just as much love and care because of this. Depending on your bowl, it's best to let your bowl cool down naturally between sessions. This avoids microfracturing - when the glaze on a bowl changes temperature rapidly, and starts cracking. This can lead to a leaky bowl, meaning glycerin can leak out of the bowl through the glaze, meaning loss of flavor. If you have only one bowl, this is kind of hard to avoid, and between sessions you can run hot water over your bowl to cool it down enough to pack. The hope with hot water is that the temperature change won't be drastically different enough to mircrofracture it. Make sure you've got all of your cooked tobacco out of your bowl, then, if you have some charred tobacco on your bowl, you can take a brillo pad or steel wool to it to get it clean. If it's really stuck on there, you can just rest it in hot water for ten minutes or so, then attempt to get it off.
Cleaning your HMD
This won't apply to everyone, but the vast majority of smokers reading this will have a Heat Management Device, like the Kaloud Lotus, Oduman Ignis, or the Shishabucks Stratus. These are probably the most annoying aspect of cleaning your hookah to clean, but nonetheless, it needs done. As I'm sure you've noticed, shisha will naturally get cooked onto the base of your HMD with regular use. While it's not necessary to clean them all the time, it's important to make sure that the vents on the device aren't covered at all, as this can restrict airflow. If you want to get a thorough clean, I've found that boiling your HMD for five or ten minutes will make the caked on tobacco extremely easy to remove. If you don't want to do that, I've found that steel wool, or a grill brush will get the job done just fine, though won't do a perfect job. Honestly, a grill brush is pretty much all I use, and it works like a charm. It's hard to get your HMD back to it's original state, but you can get it as clean as possible with this method.
Washing Your Hose
This, along with your stem, is one of the things that I don't see nearly enough of being done. First off, make sure you have a washable hose. Generally washable hoses are advertised as such, or are made of silicone. Hoses that come with Khalil Mamoon hookahs are not washable, regardless of if they look just like a nammor hose (which is washable). A good list of washable hoses includes hoses like the nammor, narbish, nagoom, d-hose series, thunder hose, and so on and so forth. Now, even if you have a washable hose, you need to actually wash it. Washing it can be as easy as running water through it when you're done smoking. If your hose is seriously ghosted, it may require a bit more effort. I'll usually take lemon juice, squirt a little down the hose, and cover both ends of the hose with my thumbs. Shake the hose around a little, then dump the lemon juice out, and run hot water through your hose. After you're done, hang the hose over a door or something to let the hose dry out. Keep in mind, water will drip from both ends of the hose while it's hung up.
That's it! See? Nothing too crazy. It's very little effort, and maximum reward. With regular maintenance, you won't have to deep clean your hookahs very often at all, and they can easily last a lifetime (provided they're good hookahs to begin with). Not to mention, your sessions will be infinitely better. As I said, it's the difference between a good session and a bad one. I don't think anyone really wants to taste a coffee flavor when they're smoking a peach flavor... Or maybe that's just me. Regardless, clean your hookah. It makes a difference. As always, thanks for reading, and happy (clean) smokes!