My bong is over 2 years old and still pristine, no one likes smoking from a dirty bong. Do yourself a favor because you (and your lungs) deserve it! Think of it as an enema, but for your bong. This method works for simple old-school bongs, bongs with diffusers are extremely difficult to wash by hand.

"What steps do I have to do to get a bong this pretty without using all the expensive chemicals that they sell in head shops?"

That was my question way back when I was a student and wanted to find a better way to clean it than just salt and warm water, because it didn't seem to clean off anything. Everyone who I asked for advice only told me to use salt and water or alcohol. I have tried the bong cleaning chemicals when I was curious, but none of them have worked better than just doing it by hand.

Back then I let my bongs go dirty and smelly, because nothing would get rid of the residue. So then I started to experiment with different ways to clean my bongs. This method has worked fine for me and it doesn't take longer than 30 minutes for a completely brown bong to get clean.

Things you'll need:

A bong
A bottle brush (if you don't have one, this will be the only thing that costs more than 5 dollars, really)
Detergent
A towel
A bucket, sink or a bath tub
Some Q-tips (or a clean toothbrush) if you really wanna be thorough

So how do you do this?

Get your bong ready. Remove any loose pieces, downstem, bowl, everything! We don't want your precious bong to break.
Fill a large bucket, sink or even a bath tub with hot water (as in it will feel hot when you touch it, but it won't burn your hands off). Find anything that the bong fits in without struggle. Don't make it fit! It will not fit. If your bong is extremely fragile I suggest you are careful with the temperature of the water. Too hot and it will break.
Add all-purpose cleaner into the water and mix it well. It should say on the label how much you should use. I suggest you use the right amount, as too much detergent won't help your case. I suggest mild, organic detergents without any added perfume. I use eucalyptus as my go to-detergent to get rid of the smell, but it is not necessary.
Carefully place your bong in the water. Make sure its all covered in the water. Get rid of air bubbles.
If the bowl and down stem are dirty, just make another mix of water and detergent into a smaller container.
Let it be for 15-20 minutes depending on how dirty it is. This is an important step, don't skip it.
Use the brush to brush the insides of the bong while its submerged in the water! Add some hot water if it's gone cold. I've noticed that lifting it up from the water only makes the bong more stained as the brush doesn't wash it, it just smears the residue everywhere. Twist and turn the brush while its inside the bong and make sure you get to every inch of it.
Use a smaller bottle brush (if you happen to have one) or q-tips to clean the downstem and the bowl. I've also used an old roughed up towel for this, as you can stuff it in the bowl and pull all the dirt out. A toothbrush is amazing too. Just make sure it's clean. Use the same technique as described in number 7.
Empty the bong and see for yourself how much dirt you got off. Keep brushing until you are satisfied, then continue to the next step.
Empty the container filled with hot water and detergent and fill it with just lukewarm water. Rinse the bong very thoroughly, you don't want any residue from the detergent. A shower works too. Just hold on to the bong and spray it for a few minutes or until you are sure it is clean enough.
Rinse and repeat on the downstem and bowl. These are extremely important as you are smoking from it and you don't wanna smoke soap. Trust me, it does smell better than it tastes.
Place the bong on a clean towel (in a safe place!) to dry. You can make the drying process faster by wiping it with paper towels, a normal shower towel usually leaves track marks.
Put the bong together.
Now test your fresh bong and be amazed how much of a difference it makes if you haven't done this in a long time!

And that's how I got all my bongs (I've owned more than 10 by now, RIP to a few of them...) clean and tasty without using any of the bong cleaners that they sell for about 15 dollars/4 oz (at least where I am staying). Thanks for reading and happy smoking sessions!

Edit: Also my first post, will be posting more on this section for sure!