So t this great bong, ive had it for just over a year and it has been great
I clean it regularly, water changing a few times a week
And iso + salt wash it every 1-2 weeks, depending how much i have been smoking
So it used to be beautifully crystal clear and i could see through the tree per
But now even after solvent + salt cleans it still has resin build up in the perc tubes
I usually use Methylated Spirits + Salt, because iso is more expensive where i live, and metho is pure alcohol anyway with stuff added to stop you drinking it, and i always thoroughly rinse it afterwards.
And it usually works really well, but lately ive wanted to get it back to brand new, but have failed....
I have tried the following methods today and nothing has worked
Soaking in boiling hot soapy water, in between Metho + salt washed
Acetone and salt
Is there anything i havent tried, or should i just resign to the fact that it will never be clean
*Note: Before anyone posts and comments, I know how to use and dispose of these chemicals safely, as well as rinsing the bong thoroughly afterwards, and have studied chemistry at University level
And yes i am sure it was full strength, i poured some on a piece of wood and washed it off seconds later with water, and it had stripped the color